IPA: /pərˈsjʊər/
KK: /pərˈsuːər/
A person who chases or follows someone or something, often with the intention of catching or achieving a goal.
The pursuer ran after the thief, determined to catch him.
Pursuer → It is formed from "pursue" (from Old French *poursuivre*, meaning to follow or chase) and "-er" (meaning a person who). A pursuer is a person who follows or chases after something.
Think of someone who is 'following' or 'chasing' something — that's what a pursuer does.