>Impossible to understand or interpret.
>Any person or thing that’s mysterious, mystifying, hard to read, or impossible to interpret
>Not readily investigated, interpreted, or understood
Inscrutable derives from the Late Latin adjective inscrutabilis, which can be traced back to the verb scrutari, meaning “to search or to examine.” “Scrutari” is also the source of the English words “scrutinize” and “scrutiny.” Incidentally, the antonym “scrutable” (“capable of being deciphered or understood”) is a part of our language as well, though it’s less common than inscrutable.
Example
>The inscrutable gaze of the palace guards made me a little nervous.
>Since I am not a computer expert, the error message on my screen is inscrutable to me.