牆頭草

Simplified: 墙头草

qiángtóucǎo ㄑㄧㄤˊ ㄊㄡˊ ㄘㄠˇ

    • sb who goes whichever way the wind blows
    • sb with no mind of their own
    • easily swayed person
    • opportunist

Character by character

Saying俗语俗語

Idiom惯用语 · In everyday use

Literally
grass on top of a wall
Meaning
A person with no firm stand who goes with whoever is stronger. Contemptuous; like 'a fence-sitter' or 'turncoat'.

Sources