What is Complainer?
Complainer definition and meaning on Dictionary terms:
verb (used without object)
to express dissatisfaction, pain, uneasiness, censure, resentment, or grief; find fault: He complained constantly about the noise in the corridor.
to tell of one’s pains, ailments, etc.: to complain of a backache.
to make a formal accusation: If you think you’ve been swindled, complain to the police.