noun Etymology: French, literally, I know not what Date: circa 1656 something that cannot be adequately described or expressed
JE NE SAIS QUOI
Meaning of JE NE SAIS QUOI in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012