confidant

US /ˈkɑːn.fə.dænt/
UK /ˈkɑːn.fə.dænt/
"confidant" picture
1.

知己, 心腹

a person with whom one shares a secret or private matter, trusting them not to repeat it to others

:
She told her deepest fears to her closest confidant.
她把内心最深的恐惧告诉了她最亲密的知己
He served as a trusted confidant to the president.
他担任总统的心腹