Čo je complaint? Čo je complaint? An expression of pain, dissatisfaction, or resentment.A cause or reason for complaining; a grievance.A bodily disorder or disease; a malady or ailment.The symptom or distress about which a patient seeks medical assistance.Law The presentation by the plaintiff in a civil action, setting forth the claim on which relief is sought.Law A formal charge, made under oath, of the commission of a crime or other such offense.