give up on sb/sth

/ɡˈɪv ˌʌp ˌɒn ˌɛsbˈiː slˈaʃ ˌɛstˌiːˈeɪtʃ/

/ɡˈɪv ˌʌp ˌɑːn ˌɛsbˈiː slˈæʃ ˌɛstˌiːˈeɪtʃ/

to give up on sb/sth

to stop believing in someone or something and lose faith in them