creep up
US /kriːp ʌp/
UK /kriːp ʌp/

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.
猫悄悄地靠近了那只鸟。
•
Prices have been creeping up steadily.
物价一直在稳步上涨。
悄悄靠近, 逐渐上涨
to move slowly and quietly so as not to be noticed