From The Collaborative International Dictionary of English v.0.48 [gcide]:
Yoni \Yo"ni\ (y[=o]"n[=e]), n. [Skr. y[=o]ni.] (Hindu Myth.)
The symbol under which Sakti, or the personification of the
female power in nature, is worshiped. Cf. Lingam.
[1913 Webster]