铁脊梁

Traditional (Taiwan): 鐵脊梁

tiějǐliang ㄊㄧㄝˇ ㄐㄧˇ ˙ㄌㄧㄤ

    • person of strong character and integrity who never bows to pressure

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
iron backbone
Meaning
A person of strong character who has integrity and never bows to pressure. Approving.

Sources