磕头虫

Traditional (Taiwan): 磕頭蟲

kētóuchóng ㄎㄜ ㄊㄡˊ ㄔㄨㄥˊ

    • person who bows and scrapes to superiors
    • toady

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
kowtow bug
Meaning
Formerly a petty official; now a person who bows and scrapes to superiors. Contemptuous.

Sources