1. n. (usually in plural) That which is deserved or merited; a just punishment or reward
2. n. A barren area of land or desolate terrain, especially one with little water or vegetation; a wasteland.
3. n. (figuratively) Any barren place or situation.
4. adj. Usually of a place: abandoned, deserted, or uninhabited.
They were marooned on a desert island in the Pacific.
5. v. To leave (anything that depends on one's presence to survive, exist, or succeed), especially when contrary to a promise or obligation; to abandon; to forsake.
You can't just drive off and desert me here, in the middle of nowhere.
6. v. To leave one's duty or post, especially to leave a military or naval unit without permission.