The Collaborative International Dictionary of English v.0.48:

Shamrock \Sham"rock\, n. [L. seamrog, seamar, trefoil, white
   clover, white honeysuckle; akin to Gael. seamrag.] (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.
   [1913 Webster]

   Note: 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).
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dutch \Dutch\, a. [D. duitsch German; or G. deutsch, orig.,
   popular, national, OD. dietsc, MHG. diutsch, tiutsch, OHG.
   diutisk, fr. diot, diota, a people, a nation; akin to AS.
   pe['o]d, OS. thiod, thioda, Goth. piuda; cf. Lith. tauta
   land, OIr. tuath people, Oscan touto. The English have
   applied the name especially to the Germanic people living
   nearest them, the Hollanders. Cf. Derrick, Teutonic.]
   Pertaining to Holland, or to its inhabitants.
   [1913 Webster]

   Dutch auction. See under Auction.

   Dutch cheese, a small, pound, hard cheese, made from skim
      milk.

   Dutch clinker, a kind of brick made in Holland. It is
      yellowish, very hard, and long and narrow in shape.

   Dutch clover (Bot.), common white clover (Trifolium
      repens), the seed of which was largely imported into
      England from Holland.

   Dutch concert, a so-called concert in which all the singers
      sing at the same time different songs. [Slang]

   Dutch courage, the courage of partial intoxication. [Slang]
      --Marryat.

   Dutch door, a door divided into two parts, horizontally, so
      arranged that the lower part can be shut and fastened,
      while the upper part remains open.

   Dutch foil, Dutch leaf, or Dutch gold, a kind of brass
      rich in copper, rolled or beaten into thin sheets, used in
      Holland to ornament toys and paper; -- called also Dutch
      mineral, Dutch metal, brass foil, and bronze leaf.


   Dutch liquid (Chem.), a thin, colorless, volatile liquid,
      C2H4Cl2, of a sweetish taste and a pleasant ethereal
      odor, produced by the union of chlorine and ethylene or
      olefiant gas; -- called also Dutch oil. It is so called
      because discovered (in 1795) by an association of four
      Hollandish chemists. See Ethylene, and Olefiant.

   Dutch oven, a tin screen for baking before an open fire or
      kitchen range; also, in the United States, a shallow iron
      kettle for baking, with a cover to hold burning coals.

   Dutch pink, chalk, or whiting dyed yellow, and used in
      distemper, and for paper staining. etc. --Weale.

   Dutch rush (Bot.), a species of horsetail rush or
      Equisetum (Equisetum hyemale) having a rough,
      siliceous surface, and used for scouring and polishing; --
      called also scouring rush, and shave grass. See
      Equisetum.

   Dutch tile, a glazed and painted ornamental tile, formerly
      much exported, and used in the jambs of chimneys and the
      like.
      [1913 Webster]

   Note: Dutch was formerly used for German.
         [1913 Webster]

               Germany is slandered to have sent none to this
               war [the Crusades] at this first voyage; and that
               other pilgrims, passing through that country,
               were mocked by the Dutch, and called fools for
               their pains.                       --Fuller.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Clover \Clo"ver\ (kl[=o]"v[~e]r), n. [OE. claver, clover, AS.
   cl[=ae]fre; akin to LG. & Dan. klever, D. klaver, G. klee,
   Sw. kl["o]fver.] (Bot.)
   A plant of different species of the genus Trifolium; as the
   common red clover, Trifolium pratense, the white,
   Trifolium repens, and the hare's foot, Trifolium arvense.
   [1913 Webster]

   Clover weevil (Zool.) a small weevil (Apion apricans),
      that destroys the seeds of clover.

   Clover worm (Zool.), the larva of a small moth (Asopia
      costalis), often very destructive to clover hay.

   In clover, in very pleasant circumstances; fortunate.
      [Colloq.]

   Sweet clover. See Meliot.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Trifolium repens
    n 1: creeping European clover having white to pink flowers and
         bright green leaves; naturalized in United States; widely
         grown for forage [syn: white clover, dutch clover,
         shamrock, Trifolium repens]