Pet″al (pĕt″al; 277), n. [Gr. πέταλον a leaf, a leaf or plate of metal, fr. πέταλοσ outspread, broad, flat: cf. F. pétale. See Fathom.] 1. (Bot.) One of the leaves of the corolla, or the colored leaves of a flower. See Corolla, and Illust. of Flower.
2. (Zoöl.) One of the expanded ambulacra which form a rosette on the black of certain Echini.