Word Study
hypanthium
CIDE DICTIONARY
hypanthium, n. [NL., fr. Gr. "ypo beneath + 'a`nqos flower.].
A fruit consisting in large part of a receptacle, enlarged below the calyx, as in the Calycanthus , the rose hip, and the pear. [1913 Webster]
For further exploring for "hypanthium" in Webster Dictionary Online