Also found in: Thesaurus, Medical, Legal, Encyclopedia.
(Zoology) a tuft of feathers attached to the first digit of a bird, distinct from the wing feathers attached to the other digits and the ulna. Also called: alula
al•u•la(ˈæl yə lə)
n., pl. -lae (-ˌli)
1. Also called bastard wing , winglet. a group of small, relatively stiff feathers at the inner end of a bird's wing.
2. a membranous lobe at the base of each wing of a dipterous insect.