Ornithology the terminal part of a bird's wing corresponding to the thumb, consisting of two or more quills; bastard wing
Origin of alulaModL, dim of ala, wing: see aileron
A small joint in the middle of a bird's wing, homologous with the thumb and bearing three or four quill-like feathers. Also called bastard wing.
Origin of alulaNew Latin, diminutive of Latin āla, wing.
(plural alulae or alulas)