Je ne sais quoi

[Little_Girl]

French: I do not know what.

As far as english speaking people are concerned, this is spoken by [snooty] types as to sound more sophisticated than they are, used humorously as such by people who do know what it means, and spoken by French when they need to say I dont know what in French.

Generally speaking, can be used if youre feeling particularly [suave] to give an explanation of something of a certain unknown or indescribable quality.

See also [unobtanium].

[Britney]

Literally it means I do not know in French. But it is actually an euphemism to express a pleasant or desirable trait about something or someone that cant be desribed or explained.

This French idiom is frowned upon by people who feel socially, economically, or mentally threatened because they cant stand snobs who use this phrase (see first definition in this list). People who fear foreign languages also have a tendency to have small reproductive organs, carry big guys to compensate for their lack of confidence, and are generally socially inept when trying to carry on an intelligent conversation with people smarter then them.

[Rihanna]

What you say when you dont know what to say, and cant be bothered to say what you think.