step aside/down
phrasal verb with step verb [ I + adv/prep ] uk/step/ us/step/ -pp-
C2 退位;下台;（尤指）让位
to leave an important job or position, especially to allow someone else to take your place
He has decided to step down as captain of the team. 他决定不再当队长。
He is unwilling to step aside in favour of a younger person. 他不愿意让位给一个比他年轻的人。