creep up

US /kriːp ʌp/
UK /kriːp ʌp/
"creep up" picture
1.

悄悄靠近, 逐渐上涨

to move slowly and quietly so as not to be noticed

:
The cat crept up on the bird.
悄悄地靠近了那只鸟。
Prices have been creeping up steadily.
物价一直在稳步上涨