Meaning of “ingratiate” - Learner’s Dictionary

ingratiate

verb uk us /ɪnˈɡreɪʃieɪt/
ingratiate yourself (with sb)

to try to make people like you by doing things to please them

ingratiating adjective

Ingratiating behaviour is done to try to make people like you:

an ingratiating smile/manner

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