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