boxer

boxer (dog)

From German Boxer.

boxer shorts; boxer engine

Borrowed from English boxer. The sense "boxer shorts" is a pseudo-anglicism, derived from the English boxer shorts; note that while boxer does exist in English to refer to boxer shorts, it only exists as an attributive in front of other nouns, and cannot function as a standalone noun.

to box (to fight against (a person) in a boxing match)

Adapted borrowing of English box + -er.