The Collaborative International Dictionary
Axillaries
Axillaries \Ax"il*la*ries\ ([a^]ks"[i^]l*l[asl]*r[i^]z), Axillars \Ax"il*lars\ ([a^]ks"[i^]l*l[~e]rz), n. pl. (Zo["o]l.) Feathers connecting the under surface of the wing and the body, and concealed by the closed wing.
Wiktionary
axillaries
n. (plural of axillar English)