IPA: /ˈvæŋkwɪʃər/
KK: /ˈvæŋkwɪʃər/
A person who defeats or overcomes someone or something, especially in a battle or competition.
The vanquisher of the champion was celebrated in the arena.
Vanquisher → It is formed from "vanquish" (from Old French *vanquir*, meaning to defeat or overcome) and "-er" (meaning a person who). A vanquisher is a person who defeats or overcomes an opponent.
Think of someone who 'defeats' ('vanquish') others — the '-er' just means a person. A vanquisher is someone who overcomes others.