Where does “脇が甘い” come from?

脇が甘い (Japanese) comes from Japanese 脇, from Old Japanese 分く.

脇が甘い (Japanese): to be vulnerable

Definitions

  1. to be vulnerable

Ancestry of “脇が甘い”, step by step

脇が甘い traces back through 3 separate lines of ancestry.

via Japanese

StepLanguageWordMeaning
1Japanesethe armpit, the underarm; the underarm area of...
2Old Japanese分く

via Japanese

StepLanguageWordMeaning
1JapaneseIndicates the subject of a sentence; conjunction;...
2Finnish-nkaForms nouns, mainly bird names (in dialects) and some toponyms

via Japanese 甘い

StepLanguageWordMeaning
1Japanese甘いsweet, sugary, mellow
Every word from Old Japanese 分くEvery word from Japanese
脇が甘い — Etymology, Origin & Word History | Etymology Explorer