The Collaborative International Dictionary
Bipinnate
Bipinnate \Bi*pin"nate\, Bipinnated \Bi*pin"na*ted\, a. [Pref. bi- + pinnate; cf. F. bipinn['e]. Cf. Bipennate.] Twice pinnate.
Wiktionary
bipinnate
a. (context botany of a leaf English) Doubly pinnate; pinnate and having leaflets that are themselves pinnate.
WordNet
bipinnate
adj. of a leaf shape; having doubly pinnate leaflets (as ferns)