Adjective

(en adjective)

Stealth]]y, furtive, [[hidden, well hidden, covert (especially movements).

* {{quote-book, year=1922, author=(Ben Travers), title=(A Cuckoo in the Nest)

, chapter=1 citation , passage=He read the letter aloud. Sophia listened with the studied air of one for whom, even in these days, a title possessed some surreptitious allurement.}}

Adjective

(en adjective)

Of unknown origin.

He received a mysterious phone call this morning.

Having unknown qualities.

Our boss is a mysterious man who hardly ever meets with us.

Difficult to understand.

Why he left without saying goodbye is quite mysterious .

Deliberately evasive or enigmatic.

Stop being mysterious and just tell me what you want.