The Collaborative International Dictionary
Carpellum
Carpel \Car"pel\ (k[aum]r"p[e^]l), ||Carpellum \Car*pel"lum\ (-p[e^]l"l[u^]m), n. [NL. carpellum, fr. Gr. karpo`s fruit.] (Bot.) A simple pistil or single-celled ovary or seed vessel, or one of the parts of a compound pistil, ovary, or seed vessel. See Illust of Carpaphore.
Wiktionary
carpellum
n. (context botany English) A carpel.