IPA: /ˈpʌn.tʃər/
KK: /ˈpʌnʧər/
A person who hits someone or something with a fist.
The puncher in the boxing match delivered a powerful blow to his opponent.
Puncher → It is formed from "punch" (from Middle English *punchen*, meaning to hit or strike) and "-er" (meaning a person who). A puncher is a person who strikes or hits.
Think of someone who 'hits' ('punch') — the '-er' just means a person. A puncher is someone who strikes.