IPA: /ˈwɪnər/
KK: /ˈwɪnər/
A person or thing that wins something, especially in competitions or contests.
She was the winner of the marathon last year.
Winner → It is formed from "win" (from Old English *winnan*, meaning to strive or labor) and "-er" (meaning a person who). A winner is a person who has strived and succeeded in a competition or challenge.
Think of someone who has 'strived' ('winnan') and succeeded — that's why a winner is a person who wins.