Meaning of “give in” - Learner’s Dictionary

give in

phrasal verb with give uk us /ɡɪv/ verb (past tense gave, past participle given)
AGREE

B1 to finally agree to what someone wants after a period when you refuse to agree:

We will never give in to terrorists' demands.
STOP

B1 to accept that you have been beaten and agree to stop competing or fighting

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