The Collaborative International Dictionary of English v.0.48:

Goldcup \Gold"cup`\ (g[=o]ld"k[u^]p`), n. (Bot.)
   The cuckoobud.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cuckoobud \Cuck"oo*bud"\ (k??k"??-b?d`), n. (Bot.)
   A species of Ranunculus (Ranunculus bulbosus); -- called
   also butterflower, buttercup, kingcup, goldcup.
   --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

goldcup
    n 1: any of various plants of the genus Ranunculus [syn:
         buttercup, butterflower, butter-flower, crowfoot,
         goldcup, kingcup]