Meaning of “flatter” - Learner’s Dictionary

flatter

verb uk us /ˈflætər/
SAY NICE THINGS [ T ]

to say nice things to someone in order to make them feel attractive or important, sometimes in a way that is not sincere:

The interviewer flattered him about his recent work.
be flattered

to feel very pleased and proud:

I am flattered to have been given this award.
She was flattered by his attention.
LOOK ATTRACTIVE [ T ]

to make someone look more attractive than usual:

That new hairstyle really flatters you.
flatter yourself

to believe something good about yourself, although it might not be true:

He flatters himself that he's a good driver.

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