The Collaborative International Dictionary of English v.0.48:
Biflagellate \Bi`fla*gel"late\, a. [Pref. bi- + flagellate.] Having two long, narrow, whiplike appendages. [1913 Webster] BiflorateWordNet (r) 3.0 (2006):
biflagellate adj 1: having two flagella; "a biflagellate zoospore"