1a statement that something is unsatisfactory or unacceptable:I intend to make an official complaintthere were complaints that the building was an eyesore
a reason for dissatisfaction:I have no complaints about the hotel
[mass noun] the expression of dissatisfaction:a letter of complainthe hasn’t any cause for complaint
Law the plaintiff’s reasons for proceeding in a civil action.
2an illness or medical condition, especially a relatively minor one:she is receiving treatment for her skin complaint
