IPA: /ˈpliːdə/
KK: /ˈplidər/
A person who makes a formal statement in a court of law, often on behalf of someone else, to argue a case or request something.
The pleader presented a strong case to the judge.
Pleader → It is formed from "plead" (from Old English *pleadian*, meaning to argue or make a plea) and "-er" (meaning a person who). A pleader is a person who argues or makes a plea, especially in a legal context.
Think of someone who is 'arguing' or 'making a plea' — that's what a pleader does, and the '-er' just means a person.