Source : Webster's Revised Unabridged Dictionary (1913)

Daisy \Dai"sy\, n.; pl. {Daisies}. [OE. dayesye, AS.
   d[ae]ges?eage day's eye, daisy. See {Day}, and {Eye}.] (Bot.)
   (a) A genus of low herbs ({Bellis}), belonging to the family
       Composit[ae]. The common English and classical daisy is
       {B. prennis}, which has a yellow disk and white or
       pinkish rays.
   (b) The whiteweed ({Chrysanthemum Leucanthemum}), the plant
       commonly called {daisy} in North America; -- called also
       {oxeye daisy}. See {Whiteweed}.

   Note: The word daisy is also used for composite plants of
         other genera, as {Erigeron}, or fleabane.

   {Michaelmas daisy} (Bot.), any plant of the genus Aster, of
      which there are many species.

   {Oxeye daisy} (Bot.), the whiteweed. See {Daisy}
   (b) .

Source : WordNet®

oxeye daisy
     n 1: similar to oxeye daisy [syn: {Leucanthemum maximum}, {Chrysanthemum
          maximum}]
     2: tall leafy-stemmed Eurasian perennial with white flowers;
        widely naturalized; often placed in genus Chrysanthemum
        [syn: {ox-eyed daisy}, {marguerite}, {moon daisy}, {white
        daisy}, {Leucanthemum vulgare}, {Chrysanthemum
        leucanthemum}]