Don’t confuse a geographical region (desert) with the final course of a meal (dessert) or the act of desertion!
(noun): The desert is uninhabited.
We found an oasis in the desert.
(adjective): The desert climate is harsh.
The desert island provided a temporary haven.
(verb): If you desert now, you will be marked a traitor.
You cannot desert your friend in her time of need.
(noun): Dessert was the highlight of the evening.
The dessert was sweet and rich.
(A term such as dessert wine is considered as a unit, so “dessert” here is not an adjective. In fact, dessertspoon is written as one word.)
Note: The expression “just deserts ” (what is deserved) is not spelled ‘desserts’–unless, of course, it’s the name of a business that only sells sweet treats!