内うち股また膏こう薬やく

also: うちまたごうやく

Meanings

A yojijukugo describing a person who opportunistically switches sides or tries to please both parties in a conflict. Literally 'a plaster on the inner thigh', evoking something that sticks to one side then the other. Often used in political or personal contexts.

彼かれは内うち股また膏こう薬やくで、上じょう司しの前まえではいつも意い見けんを変かえる。
He's a fence-sitter who always changes his opinion in front of his boss.
あの政せい治じ家かは内うち股また膏こう薬やくと言いわれ、与よ党とうにも野や党とうにもいい顔かおをする。
That politician is called a double-dealer, trying to stay in favor with both the ruling and opposition parties.

Kanji

内inside, within, between
股thigh, crotch
膏fat, grease, lard
薬medicine, chemical, enamel

Related words

日ひ和より見み
日和見 also means opportunism or fence-sitting, but is more neutral and can refer to a wait-and-see attitude rather than active duplicity.
二ふた股また膏ごう薬やく
A similar expression meaning 'double-dealer', literally 'a plaster on both thighs'. 内股膏薬 emphasizes moving between two sides, while 二股膏薬 stresses serving two masters simultaneously.

Built from

内うち股また+膏こう薬やく

Written forms

内股膏薬
- うちまたこうやく
  Standard kanji spelling for this yojijukugo.
- うちまたごうやく
  Alternate reading; ごうやく is a less common reading of 膏薬.
うちまたごうやく

Etymology

A yojijukugo combining 内股 (inner thigh) and 膏薬 (plaster, ointment). The image is of a medicinal plaster that is applied to one inner thigh and then shifted to the other, metaphorically describing a person who changes allegiance or opinion to suit the situation. The exact origin is uncertain, but it is a traditional Japanese idiom.