Emily Dickinson Lexicon

PET'AL, n. [Fr. petale; Gr. πεταλον, from πεταω, to expand, L. pateo. Class Bd, No. 65, &c.]

In botany, a flower leaf; the separate parts of a corol. When a corol consists of but one piece, it is said to be monopetalous, when of two pieces, dipetalous, &c.