bĭpennis (-pinnis), e, adj. [bispenna],
having two wings , two-winged (very rare): insectum, Plin. 11, 28, 33, § 96 (cf. just before, binis advolat pinnis): plumae, Varr. ap. Non. p. 79, 17.
bipennis e, adj.bi-+penna, with two edges, two-edged : ferrum, V.— As subst f . (sc. securis), wit...
An Elementary Latin Dictionary
·noun An ax with an edge or blade on each side of the handle. ...
Webster's Dictionary of the English Language