The Collaborative International Dictionary
Fabellae
Fabella \Fa*bel"la\, n.; pl. Fabellae (-l[=e]). [NL., dim. of L. faba a bean.] (Anat.) One of the small sesamoid bones situated behind the condyles of the femur, in some mammals.
Wiktionary
fabellae
n. (en-irregular plural of: fabella)