软壳虫

Traditional (Taiwan): 軟殼蟲

ruǎnkéchóng ㄖㄨㄢˇ ㄎㄜˊ ㄔㄨㄥˊ

    • weak, timid person
    • wimp

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
a soft-shelled bug
Meaning
A weak-natured, timid person. Mildly contemptuous.

Sources