let on

US /lɛt ɑn/
UK /lɛt ɑn/
"let on" picture
1.

泄露, 透露

to reveal a secret or information

:
Don't let on that you know about the surprise party.
不要泄露你知道惊喜派对的事。
She tried not to let on how upset she was.
她尽量不表露她有多沮丧。