IPA: /ˈpleɪn.tɪf/
KK: /ˈpleɪntɪf/
A person who starts a legal case against someone in court.
The plaintiff presented strong evidence to support their claim.
Plaintiff → It is derived from the Old French word 'plaintif' (meaning one who complains) which comes from 'plaint' (meaning complaint) and the suffix '-if' (indicating a person). A plaintiff is a person who brings a complaint or lawsuit to court.
Think of someone who is 'complaining' ('plaint') in a legal context — that's why a plaintiff is the person who brings a complaint to court.