◆唇歯輔車 Shinshi-hosha.
- 解釈：互いに助け合って成り立つ関係。「唇歯」は唇と歯、「輔車」は頬骨と歯茎（はぐき）のことで、片方が失われれば、他方も立ち行かない密接な利害関係。
- Literal：It is a relation of "a lip, a tooth", and "cheekbones and the gum."
- Interpretation：It is in the close interest in which another side is not materialized, either, if one of the two is lost.
- 類義：唇滅びて、歯寒し。