IPA: /ˈfaɪtər/
KK: /ˈfaɪtər/
A person or thing that fights, often in a determined or aggressive way, such as a soldier, boxer, or a combat aircraft.
The fighter trained hard for the championship match.
Fighter → It is formed from "fight" (from Old English *feohtan*, meaning to engage in combat) and "-er" (meaning a person who). A fighter is a person who engages in combat or struggle.
Think of someone who 'engages in combat' — 'fight' means to struggle, and '-er' indicates a person. This helps you remember that a fighter is someone who fights.