• WordNet 3.6
    • n shamrock clover native to Ireland with yellowish flowers; often considered the true or original shamrock
    • n shamrock creeping European clover having white to pink flowers and bright green leaves; naturalized in United States; widely grown for forage
    • n shamrock Eurasian plant with heart-shaped trifoliate leaves and white purple-veined flowers
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Webster's Revised Unabridged Dictionary
  • Interesting fact: St. Patrick explained the Holy Trinity to King Laoghaire, using the shamrock to illustrate the trinity
    • n Shamrock (Bot) A trifoliate plant used as a national emblem by the Irish. The legend is that St. Patrick once plucked a leaf of it for use in illustrating the doctrine of the trinity.☞ The original plant was probably a kind of wood sorrel (Oxalis Acetocella); but now the name is given to the white clover (Trifolium repens), and the black medic (Medicago lupulina).
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Century Dictionary and Cyclopedia
    • n shamrock A plant with trifoliate leaves: the national emblem of Ireland. According to recent authority (Britten and Holland, “English Plant Names”) the plant at the present day most in repute as the true shamrock is one of the hop-clovers, Trifolium minus, a slender trailing species with small yellow beads, perhaps a, variety of T. procumbens. It is in use in many counties of Ireland, and forms a great part of the shamrock sold in London on St. Patrick's day. The black medic, Medicago lupulina, is also thus used; but the white clover, T. repens, is widely understood to be the common shamrock. The identity of the original shamrock which, according to tradition, St. Patrick used to illustrate the doctrine of the Trinity is uncertain. It has been variously supposed to be the common white clover. T. repens (which, however, is believed to be of late introduction in Ireland); the red clover, T. pratense; the wood-sorrel, Oxalis Aceto sella (locally called shamrock in England); and even the water-cress (though its leaves are not trifoliate).
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Chambers's Twentieth Century Dictionary
    • n Shamrock sham′rok the national emblem of Ireland, a leaf with three leaflets, or plant having such leaves, sometimes supposed to be the Wood-sorrel, but the name is more frequently applied to some species of Clover, or to some common plant of some of the nearly allied genera, as the Bird's Foot Trefoil or the Black Medick. The Lesser Yellow Trefoil is the plant usually sold in Dublin on St Patrick's Day.
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Webster's Revised Unabridged Dictionary
L. seamrog, seamar, trefoil, white clover, white honeysuckle; akin to Gael. seamrag,
Chambers's Twentieth Century Dictionary
Ir. seamrog, Gael. seamrag, trefoil, dim. of seamar, trefoil.


In literature:

I'm wild to begin myself, and I'm about as green as any old shamrock.
"Miss Pat at School" by Pemberton Ginther
I can't tell you, even, the difference between a shamrock and a clover.
"The Flaw in the Sapphire" by Charles M. Snyder
"Four Young Explorers" by Oliver Optic
March, the shamrock, as complimentary to St. Patrick.
"Games For All Occasions" by Mary E. Blain
"Freaks of Fortune" by Oliver Optic
The shamrock and lily were blended as in the necklace.
"Fairy Fingers" by Anna Cora Mowatt Ritchie
"The Second Battalion Royal Dublin Fusiliers in the South African War" by Cecil Francis Romer and Arthur Edward Mainwaring
It is a representation of the common clover, or shamrock, as the Irish call it.
"The Worship of the Church" by Jacob A. Regester
Digby Street and Shamrock House were the culminating stroke to Joan's depression.
"To Love" by Margaret Peterson
Ivy won't, though shamrock will; and daisies won't, though lilies will.
"The Crown of Wild Olive" by John Ruskin

In poetry:

I. Why sleeps the Harp of Erin's pride?
Why with'ring droops its Shamrock wreath?
Why has that song of sweetness died
Which Erin's Harp alone can breathe?
"The Irish Harp" by Sydney Owenson
A withered shamrock, yet to me 'tis fair
As the sweet rose to other eyes might be,
Because its leaves spread in my native air,
And the same land gave birth to it and me.
"Lines To A Shamrock" by Nora Pembroke
Such fair broad meadows by Maine water lay,
Erin her mantle green for carpet spread,
In merry childhood there we met to play,
Dashing the dew from many a shamrock's head.
"Lines To A Shamrock" by Nora Pembroke
Green as the Shamrock of their native Isle
Their memory lives, and babes unborn shall smile
And share in happiness the pride that blends
Our country's name with her beloved friends!
"Prologue" by John Douglas Sutherland Campbell
The landscape, emerald tinted,
Lying smiling in the sun,
The grass with daisies sprinkled,
And with shamrocks over run,
The Maine water flashed and dimpled,
Still flowing softly on.
"My Own Green Land" by Nora Pembroke
And Erin spread her skirt across her grave,
And there were shamrocks nestling on the breast,
And blue bells and all flowers that softly wave,
Making more beautiful her place of rest.
"Lines To A Shamrock" by Nora Pembroke

In news:

Explosion rocks Shamrock RV park.
Shamrocks compete in Mankato Loyola cross country invite.
Fans have fun at Power Plant Live with headliners Girl Talk at the Shamrocks and Shenanigans bash on St Patrick's Day.
Humble Police said they received a call from employees of Shamrocks Pub on Oct 4, 2012 about Payne's behavior, according to KTRK.
A private graveside service will be held at Shamrock Union Cemetery, Town of Manchester, rural Black River Falls.
Shamrock Broadcasting has resurrected the format after Wilks Broadcasting dropped it last year from 100.9FM.
Shepherd's Pie, Shamrock's and Shillelagh's: A St Patrick's Day Feast.
The Thistle & Shamrock RSS.
(Four or ?ve shamrocks will ?t on each cookie sheet.).
When the cookies are cooled frost with shamrock icing.
McDonald's Cult-Favorite Shamrock Shake Returns.
Shamrock Scavenger Hunt- Monday's Clue.
Fiona Ritchie picks new Celtic music releases for The Thistle & Shamrock .
Find more information about The Thistle and Shamrock .
At first, the Shamrock Shake from McDonald's sounds like a fun time.

In science:

Our results concern the exterior of a shamrock (as its interior has no lozenge tilings).
A dual of MacMahon's theorem on plane partitions
Let S (a, b, c, m) be the shamrock whose central equilateral triangle has side-length m, while its top, bottom left and bottom right lobes are equilateral triangles of side-lengths a, b and c, respectively; denote its exterior by S ∗(a, b, c, m).
A dual of MacMahon's theorem on plane partitions
We define the ratio of the number of tilings of the exteriors of the shamrocks S (a, b, c, m) and S (a+b+c, 0, 0, m) as follows.
A dual of MacMahon's theorem on plane partitions
Let HN (a, b, c, m) be the hexagonal region of side-lengths alternating between N + a+ b+ c and N + a+ b+ c+m (the top side being N + a+ b+ c), and having the shamrock S (a, b, c, m) removed from its center (to be precise, HN (a, b, c, m) is the region SCN ,N ,N (a, b, c, m) described in the next section).
A dual of MacMahon's theorem on plane partitions
The family of regions we will be concerned with in this paper is a generalization of cored hexagons, corresponding to the case when the core is not just a triangle, but a shamrock.
A dual of MacMahon's theorem on plane partitions