• Construction of a Knock-Down Book-Shelf Seen From the Back
    Construction of a Knock-Down Book-Shelf Seen From the Back
  • WordNet 3.6
    • v knock find fault with; express criticism of; point out real or perceived flaws "The paper criticized the new movie","Don't knock the food--it's free"
    • v knock deliver a sharp blow or push :"He knocked the glass clear across the room"
    • v knock knock against with force or violence "My car bumped into the tree"
    • v knock rap with the knuckles "knock on the door"
    • v knock sound like a car engine that is firing too early "the car pinged when I put in low-octane gasoline","The car pinked when the ignition was too far retarded"
    • v knock make light, repeated taps on a surface "he was tapping his fingers on the table impatiently"
    • n knock the act of hitting vigorously "he gave the table a whack"
    • n knock negative criticism
    • n knock a bad experience "the school of hard knocks"
    • n knock the sound of knocking (as on a door or in an engine or bearing) "the knocking grew louder"
    • n knock a vigorous blow "the sudden knock floored him","he took a bash right in his face","he got a bang on the head"
    • ***

Additional illustrations & photos:

The Knock-down Blow The Knock-down Blow
Miss Fabia, the Younger, astonished at the Patrician's double-knock Miss Fabia, the Younger, astonished at the Patrician's double-knock
Who are you who dare to knock at my door Who are you who dare to knock at my door
William, knocking into his father while not looking where he is going William, knocking into his father while not looking where he is going

Webster's Revised Unabridged Dictionary
  • Interesting fact: The game of squash originated in the United Kingdom. It came about after a few boys, who were waiting for their turn to play racquets, knocked a ball around in a confined area adjoining the racquets court
    • Knock A blow; a stroke with something hard or heavy; a jar.
    • Knock A stroke, as on a door for admittance; a rap. "A knock at the door.""A loud cry or some great knock ."
    • Knock To criticise; to find fault with; to disparage. "Don't knock it if you haven't tried it."
    • Knock To drive or be driven against something; to strike against something; to clash; as, one heavy body knocks against another.
    • Knock To impress strongly or forcibly; to astonish; to move to admiration or applause.
    • Knock To practice evil speaking or fault-finding; to criticize habitually or captiously.
    • Knock To strike for admittance; to rap upon, as a door. "Master, knock the door hard."
    • Knock To strike or beat with something hard or heavy; to rap; as, to knock with a club; to knock on the door. "For harbor at a thousand doors they knocked .""Seek, and ye shall find; knock , and it shall be opened unto you."
    • Knock To strike with something hard or heavy; to move by striking; to drive (a thing) against something; as, to knock a ball with a bat; to knock the head against a post; to knock a lamp off the table. "When heroes knock their knotty heads together."
    • ***
Century Dictionary and Cyclopedia
  • Interesting fact: The first ring donuts were produced in 1847 by a 15 year old baker's apprentice, Hanson Gregory, who knocked the soggy center out of a fried doughnut.
    • knock To strike or beat; give a blow or blows to; hit; affect in some way by striking or hitting: as, to knock a ball with a bat; to knock a man senseless; he knocked me down; to knock out one's brains.
    • knock To use in striking; give a blow or blows with; bring into collision; dash: as, to knock the head against a post.
    • knock Nautical, to lay (a ship) on her side, as a gust or gale.
    • knock To accomplish hastily; put out of hand.
    • knock To deduct : as, to knock off ten cents from the price. [Colloq.l
    • knock In bookbinding, to make even the edges of, as a quantity of printed sheets, by striking them on a table while held loosely upright in the hands.
    • knock To construct hastily, as by nailing.
    • knock To strike a blow with the fist or with something hard or heavy; specifically, to rap upon a door or gate, as with the knuckles or a knocker, in order to attract the attention of those within.
    • knock To move or be moved so as to come in collision with something; strike; clash: as, one heavy body knocks against another; his knees knocked together from fright.
    • knock To smite upon the breast, as in penitence.
    • knock To die.
    • n knock A blow; a buffet; a stroke with the fist, or with anything hard or heavy, as a cudgel, a hammer, or the knocker of a door.
    • n knock A clock.
    • knock To speak ill of one.
    • knock See the extract.
    • knock To keep up a system of annoying attacks; to keep striking or hitting until the other side capitulates or buys the ‘knocker’ off.
    • ***
Chambers's Twentieth Century Dictionary
  • Interesting fact: The trainees are thrown into a pool with their hands and feet tied wearing snorkeling masks. They are then harassed by their instructors who knock their masks off, spin their bodies, and pull them under in an effort to disorient the student.
    • v.i Knock nok to strike with something hard or heavy: to drive or be driven against: to strike for admittance: to rap
    • v.t Knock to strike: to drive against
    • n Knock a sudden stroke: a rap
    • ***


  • Arnold Toynbee
    Arnold Toynbee
    “America is a large, friendly dog in a very small room. Every time it wags its tail, it knocks over a chair.”
  • John Boyle O'Reilly
    John Boyle O'Reilly
    “You gave me the key of your heart, my love; then why did you make me knock? Oh that was yesterday, saints above! And last night -- I changed the lock!”
  • Chinese Proverb
    Chinese Proverb
    “Clear conscience never fears midnight knocking.”
  • Vince Lombardi
    “It's not whether you get knocked down, it's whether you get up.”
  • Oliver Wendell Holmes
    “Every real thought on every real subject knocks the wind out of somebody or other.”
  • Frank Tyger
    Frank Tyger
    “Learn to listen. Opportunity could be knocking at your door very softly.”


Fortune knocks once at every man's door - Everyone gets one good chance in a lifetime.
Knock 'em dead - 'Knock 'em dead' is used as a way of wishing someone luck before they give a performance or have to appear before people, as in an interview, etc. ('em = them)
Knock into a cocked hat - If you knock something or someone into a cocked hat, you are much better.
Knock on wood - This idiom is used to wish for good luck. ('Touch wood' is also used.)
Knock something on the head - If you knock something on the head, you stop it or stop doing it.
Knock the pins from under someone - If someone knocks the pins from under you, they let you down.
Knock your block off - To punch someone in the face Eg : The next time you do something like that I'm going to "knock your block off".
Knock your socks off - If something knocks your socks off, it amazes and surprises you, usually in a positive way.
On the knock - (UK) If you buy something on the knock, you pay for it in instalments.
Opportunity knocks but once - This idiom means that you only get one chance to achieve what you really want to do.
You could have knocked me down with a feather - This idiom is used to mean that the person was very shocked or surprised.


Webster's Revised Unabridged Dictionary
OE. knoken, AS. cnocian, cnucian,; prob. of imitative origin; cf. Sw. knacka,. Cf. Knack


In literature:

What good would he have got had he fought the pirates, even though he had knocked them to pieces?
"Will Weatherhelm" by W.H.G. Kingston
Accordingly he descended to the cabin and knocked for admission.
"Snarley-yow" by Frederick Marryat
Indeed I am, for I didn't mean to knock you down.
"Dusty Diamonds Cut and Polished" by R.M. Ballantyne
Tess stepped shivering to the door and knocked.
"Tess of the Storm Country" by Grace Miller White
There was a bell on my door, but she did not ring, but knocked very softly.
"The Best Short Stories of 1920" by Various
Then they brought up on a big pile of decayed leaves and lay there, the breath all but knocked out of them.
"The Rover Boys on the Farm" by Arthur M. Winfield (AKA Edward Stratemeyer)
I could get no answer, although I knocked loudly two or three times; so I opened the door.
"The Grell Mystery" by Frank Froest
The knock is repeated loudly, and the bell rings.
"Oswald Langdon" by Carson Jay Lee
It was a beautiful blow, and Buckhorn was knocked over in a twinkling, striking heavily on his shoulder in the dust of the street.
"Frank Merriwell's Bravery" by Burt L. Standish
My pride was knocked flat as well as my pocket book.
"Fair Harbor" by Joseph Crosby Lincoln

In poetry:

Again he softly knock'd and call'd,
But still no answer came;
All night he watched beside the door,
Still calling on her name.
"A Ballad" by Janet Hamilton
Nor all the revellers, though dear,
Who beat my doors with prayers,
But sing so sweet they cannot hear
The poor who knock at theirs:
"Bacchus [Excerpt]" by Bernard O Dowd
Thou wilt open the door of patience,
When sorry shall come and knock;
But to every evil, unworthy thing
Wilt thou the gates fast lock.
"Thora" by Celia Laighton Thaxter
She has ta'en her young son in her arms,
And to the door she's gone,
And lang she's knocked and sair she ca'd,
But answer got she none.
"Love Gregor; Or, The Lass Of Lochroyan" by Andrew Lang
Ae Saturday nicht, a wee ere twal',
As Grizzy an' Gibby sat,
A' at ance cam' a queer, queer knock to the door,
That wauken'd up the cat.
"The Fiddler O' Boglebriggs" by Alexander Anderson
And so loud these Saxon gleemen
Sang to slaves the songs of freemen,
That the storm was heard but faintly,
Knocking at the castle-gates.
"The Norman Baron" by Henry Wadsworth Longfellow

In news:

Braves knock off Borah 38-24 in first game played at the new stadium.
When opportunity knocked in 2009, she opened the door to her Lakewood home.
Opportunity is still knocking to create a truly inspired outdoor space by simply selecting the right patio door .
A suspected drug dealer surprised cops when he answered their knock on the door with a present.
A heavy downpour that swept through the region on Sunday night knocked down several trees, including one that toppled onto a car at the Susquehanna Campground on Susquehanna Drive in Piatt Township.
Dublin City School District Superintendent David Axner (left) has been knocking on doors to talk to residents about Issue 48.
Mars' Shifty Sand Dunes Knocked Down by Dry Ice .
Germantown knocks off defending state champs.
Tony Dungy returned Rex Ryan's call and the two spoke "man to man," according to the Jets coach, about Dungy 's criticism of his language on HBO's all-access show, "Hard Knocks".
View full size Kevin Rivoli / AP New York Jets head coach Rex Ryan talks with defensive back Antonio Cromartie, right, as an HBO 'Hard Knocks' film crew records the conversation during training camp in Cortland on August 4.
Texans QB Matt Schaub was hit so hard Sunday it knocked his helmet off, and with that came part of his ear.
Ninety-mile-per-hour winds knock power out across Eastern US amid record heat wave.
Waterford effortlessly knocks out North Sanpete.
"I ran outside and plowed into him" knocking his father off the levers.
(WBNG Binghamton) It's designed to help you get fit, but this machine could knock you out of commission.

In science:

In the knockout reaction a nucleon at the surface of the pro jectile is knocked out of its orbital by a peripheral collision with the target nucleus.
New magic numbers
The cross-section for the knock-out reaction can be reliably calculated using Glauber theory and can be used as a measure of the occupation of the orbital, which can be compared with the predication of shell model calculations.
New magic numbers
Thus in Path 1 we can think of a new ion coming in and knocking the present ion out the other side.
From Brownian Dynamics to Markov Chain: an Ion Channel Example
E > 0.1 MeV) generate collision cascades in cuprates by transferring suļ¬ƒcient energy to a primary knock-on atom, which initiates further collisions .
Stress dependence of the critical currents in neutron irradiated (RE)BCO coated conductors
Epithermal neutrons (in the keV range) may create point defects or clusters, if the recoil energy of the primary knock-on atom is high enough to displace at least one atom.
Stress dependence of the critical currents in neutron irradiated (RE)BCO coated conductors