Meaning of “complaint” - Learner’s Dictionary

complaint

noun uk us /kəmˈpleɪnt/
NOT SATISFACTORY [ C, U ]

B1 a statement that something is wrong or not satisfactory:

a letter of complaint
I wish to make a complaint.
We received several complaints about the noise.
ANNOYING THING [ C ]

something that makes you complain:

My only complaint was the lack of refreshments.
ILLNESS [ C ]

an illness:

a stomach complaint

(Definition of “complaint” from the Cambridge Learner’s Dictionary © Cambridge University Press)