Adjective
Used other than figuratively or idiomatically: see female, to, male.
the female-to-male ratio is 3-to-5
(LGBT) Transitioning or having transitioned from being physically female to being male.
(LGBT) Changing or having changed from having a female gender (gender identity or presentation) to being male.
(electronics, of an adapter) That changes a female end (usually a socket) of a connection into a male one (with pins, usually a plug).
Source: en.wiktionary.org