Source : Webster's Revised Unabridged Dictionary (1913)

Moonflower \Moon"flow`er\, n. (Bot.)
   (a) The oxeye daisy; -- called also {moon daisy}.
   (b) A kind of morning glory ({Ipom[oe]a Bona-nox}) with large
       white flowers opening at night.

Source : WordNet®

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