Synonyms for Complaint:

n.

contagion, epidemic. beef, happy, gripe, grouse, rant. accusation (noun)
indictment, censure, charge, accusation, citation, impeachment, allegation, incrimination, allegement, denouncement, grievance, insinuation, reproach, accusal, imputation, condemnation, criticism, blame.
blame (noun)
reproach.
complaint (noun)
ill, charge, ailment.
condemnation (noun)
blame.
disagreement (noun)
repudiation, dissent, contention, defiance, disagreement, disaccord, divisiveness, argument, opposition, conflict, dispute, rejection, nonagreement, disunity, challenge.
disease (noun)
ailment, spasm, symptom, attack, syndrome, infliction, sickness, illness, bug, pestilence, curse, disorder, decrepitude, disease, indisposition, infirmity, feverishness, virus, breakdown, apoplexy, queasiness, ague, nausea, complication, collapse, infection, debility, condition, affection, unhealthiness, handicap, Sickliness, disability, fever, malaise, malady.
illness, affliction (noun)
ailment, disorder, sickness, syndrome, malady, affection, ill, disease, infirmity, indisposition, condition.
lawsuit (noun)
summons, writ, litigation, affidavit, subpoena, implication, lawsuit, action, case, hearing, count, prosecution, suit, arraignment.
protest (noun)
ridicule, objection, protest, lamentation, detraction, denigration, disparagement, scold, deprecation.
statement of disagreement, discontent (noun)
protest, gripe, reproach, grievance, grouse, charge, objection, accusation, beef, criticism.

Other synonyms:

rant, gripe, contagion. epidemic. beef. Other relevant words:
beef, grouse, contagion, gripe, ill.

Usage examples for complaint

  1. You're a good fellow, doctor; and you do understand my complaint don't you?" – The Man with a Shadow by George Manville Fenn