• WordNet 3.6
    • adj challengeable capable of being challenged
    • ***
Webster's Revised Unabridged Dictionary
  • Interesting fact: Seven asteroids were especially named for the Challenger astronauts who were killed in the 1986 failed launch of the space shuttle
    • a Challengeable That may be challenged.
    • ***
Century Dictionary and Cyclopedia
  • Interesting fact: In Washington D.C. it is illegal to post a notice in public which calls another person a 'coward' for refusing to accept a challenge to duel.
    • challengeable Capable of being challenged, or called to an account.
    • ***
Chambers's Twentieth Century Dictionary
  • Interesting fact: The term "throw one's hat in the ring" comes from boxing, where throwing a hat into the ring once signified a challenge. Today it nearly always signifies political candidacy.
    • adj Challengeable that may be challenged
    • ***


  • Marcel Proust
    “A powerful idea communicates some of its strength to him who challenges it.”
  • Peter F. Drucker
    “Knowledge has to be improved, challenged, and increased constantly, or it vanishes.”
  • Viktor E. Frankl
    Viktor E. Frankl
    “Challenging the meaning of life is the truest expression of the state of being human.”
  • Mary Ann Allison
    Mary Ann Allison
    “Hire the best. Pay them fairly. Communicate frequently. Provide challenges and rewards. Believe in them. Get out of their way and they'll knock your socks off.”
  • Amelia Earhart
    Amelia Earhart
    “Women must try to do things as men have tried. When they fail their failure must be but a challenge to others.”
  • Cleveland Amory
    Cleveland Amory
    “A supreme social challenge.”


Chambers's Twentieth Century Dictionary
O. Fr. chalenge, a dispute, a claim—L. calumnia, a false accusation—calvi, calvĕre, to deceive.


In literature:

This seemed like a challenge.
"The Watchers of the Trails" by Charles G. D. Roberts
It responded not to challenge, and visual contact obscene horror showed.
"Fearful Symmetry" by Ann Wilson
An old word for to challenge, or incite to emulation; still in full use.
"The Sailor's Word-Book" by William Henry Smyth
In 1808 challenged Humphrey Marshall, and fired three times at his breast.
"Robert Toombs" by Pleasant A. Stovall
Whom are you about to challenge?
"Her Mother's Secret" by Emma D. E. N. Southworth
This was an out and out challenge to him to strike her.
"The Huntress" by Hulbert Footner
They've sent us a challenge.
"The Hero of Garside School" by J. Harwood Panting
They will bring their own wares, and challenge a trial: they want nothing but to name the judges.
"A Budget of Paradoxes, Volume II (of II)" by Augustus de Morgan
And you need not stop, if challenged.
"The Boy Scout Automobilists" by Robert Maitland
Jaime passed by the forge, staring at the Ironworker, giving a look of challenge which the other seemed not to understand.
"The Dead Command" by Vicente Blasco Ibáñez

In poetry:

New hands the wires of song may sweep,
New voices challenge fame;
But let no moss of years o'ercreep
The lines of Halleck's name.
"Fitz-Greene Halleck" by John Greenleaf Whittier
Hence though the law condemn at large,
It can lay nothing to my charge;
Nor find such ground to challenge me,
As Heaven hath found justify.
"The Believer's Riddle; or, the Mystery of Faith" by Ralph Erskine
Haste! The brave steed, leaping lightly,
'Neath his double burden sprightly,
Challenges, with scornful note,
Every horse in Pharaoh's boat.
"Lita of the Nile" by Richard Doddridge Blackmore
His state-craft was the Golden Rule,
His right of vote a sacred trust;
Clear, over threat and ridicule,
All heard his challenge: "Is it just?"
"Sumner" by John Greenleaf Whittier
'Tis the Philistine,
Proclaiming by his herald, through the ranks,
His near approach. Each morning he appears
His challenge to our bands.
"David And Goliath. A Sacred Drama" by Hannah More
And as the Epic lifts a form sublime
For all the Ages on its plinth of gold,
So does our Story, challenging all time,
Its crowning shape uphold!
"Arms And The Man - Heroes And Statesmen" by James Barron Hope

In news:

Huawei Challenges the iPhone With the Ascend D. Skype disables password reset after security flaw exposed.
America's Ultimate Challenge: The Pikes Peak Ascent (McKenzie Martin).
They call it America's Ultimate Challenge and I have to admit they are right.
CTFA Preservative Challenge and Stability Testing Survey.
Landmark Accord Could Challenge US Influence in Southeast Asia by 2010.
The Abnormal Situation Management ( ASM ) Consortium recently gathered for a quarterly meeting to discuss challenges faced by plant operators.
Tracking down ancestors is a rewarding challenge.
Scholars Challenge Author's Assertion That 1960s Activist Worked for FBI.
Paraguay action film thrills and challenges.
Schwannomas of the nasal septum are extremely rare, and therefore their diagnosis and treatment can pose certain challenges.
Driving down St Bernard Avenue between Filmore and Robert E Lee is a challenge.
A metric century is a 100 kilometer cycling event that is done for fun and challenge 100km events are just about the perfect distance to start as a great cycling challenge.
In fact, both skin care professionals—who lament the challenges of treating hyperpigmented skin—and clients—who suffer through years of unsuccessful attempts at eliminating it—are challenged by this condition.
Finances, youth, energy, environment, land use are interwoven challenges Mayor Pat Burt outlines city priorities, challenges during the annual.
Jordanian charter operator Rayajet has placed firm orders with Bombardier for a Challenger 300 and one of the larger Challenger 605s.

In science:

Thus it is a challenging open problem to define four manifold invariants beyond Donaldson-Witten or Seiberg-Witten invariants.
Higgs Bundles and Four Manifolds
While we have seen that the matching parameter y (α) and the kernel-size parameter z (α) are well understood and closely related, the exact evaluation of vertex cover parameter x(α) remains as a challenge.
Core percolation in random graphs: a critical phenomena analysis
Modelling the universe presents some new challenges for the applied mathematician or theoretical physicist different from those in other areas of the mathematical modelling of physical phenomena.
Is Nature Generic?
The challenge faced by Einstein and his colleagues was to mount an argument built directly on the orthodox quantum principles themselves.
Quantum theory and the role of mind in nature
The study of such hard instances represent a theoretical challenge towards a concrete understanding of complexity and the analysis of algorithms.
Phase coexistence and finite-size scaling in random combinatorial problems