pennŭla, ae, f. dim. [penna],
a little wing (rare but class.): cum pulli pennulis uti possunt, Cic. N. D. 2, 52, 129: tensa, Ven. Carm. 3, 22, 9; Hieron. adv. Pelag. 1, 14 init. ; Vulg. Lev. 5, 8.
pennula see pinnula. ...
An Elementary Latin Dictionary