boxer

The word 'boxer' is a transparent agent noun formation from the verb 'to box', meaning to fight with the fists. The verb 'box' itself emerged in Middle English, possibly as an onomatopoeic term evoking the sound of a punch. The '-er' suffix, a prolific agent-noun marker in English, straightforwardly indicates 'one who boxes'. The term for the dog breed, originating in Germany in the late 19th century, was adopted into English due to the animal's pugnacious appearance and stance, which was likened to that of a human boxer.

Structure: box (to strike with the fists) + er (agent noun suffix) 'box' (verb) originates from Middle English 'boxen', likely imitative of the sound of a slap or blow. 'er' is an agentive suffix from Old English '-ere', of Germanic origin, used to form nouns denoting a person or thing that performs an action.