| Complainant 1. (n.) One who makes complaint. 2. (n.) One who commences a legal process by a complaint. 3. (n.) The party suing in equity, answering to the plaintiff at common law. Thesaurus Entries accusant, accuser, allegator, appellant, bellyacher, claimant, complainer, crab, crank, croaker, delator, faultfinder, frondeur, griper, grouch, grouser, growler, grumbler, impeacher, impugner, indictor, informer, kicker, kvetch, libelant, malcontent, murmurer, mutterer, party, petitioner, plaintiff, prosecutor, querulous person, reactionary, reactionist, rebel, sorehead, suitor, the prosecution, whiner |