slip someone's mind
US /slɪp ˈsʌm.wʌnz maɪnd/
UK /slɪp ˈsʌm.wʌnz maɪnd/

1.
잊어버리다, 깜빡하다
if something slips your mind, you forget it
:
•
I meant to call her, but it completely slipped my mind.
그녀에게 전화하려고 했는데, 완전히 잊어버렸어.
•
The meeting time must have slipped his mind.
회의 시간이 그에게서 잊혀졌을 거야.