(uncountable) The attribute or characteristic of acting in secrecy, or in such a way that the actions are unnoticed or difficult to detect by others.

(especially military, computing) To conceal or infiltrate through the use of stealth.

(slang, intransitive) To have sexual intercourse without a condom through deception (for example, removing the condom mid-act).

Surreptitious; secret; not openly acknowledged.

(military, aviation, vehicles, technology) Having properties that diminish radar signatures.

(transgender) Hiding one's transgender status (in general or in specific areas of one's life, e.g. at work) after transition.