This is a confusing set of homophones. 

Dessert is  the sweet course eaten at the end of a meal. What’s your favourite? I’m an absolute sucker for lemon meringue pie, but I also love a creamy lemon cheesecake.  A dessert wine is, similarly, sweet and intended to be enjoyed after a meal. 

The key thing to remember is that this is the only meaning for this spelling.

Fun fact: ‘desserts’ is ‘stressed’ spelt backwards, and an anagram of ‘de-stress’.  
I don’t know about you, but I do not believe that can be a coincidence.

The word ‘desert’ is used when someone gets what they deserve, and it is said they have “got their just deserts”. It is usually used in a punitive way – ‘getting your just desert’ is generally not considered to be a pleasant experience. 

Because this is a “thing” that happens, this use of the word is also a noun. 

Fun fact: this is a phrase that came to us from French via  Shakespeare, who used it in Sonnet 72, albeit in a more positive way than is usually done. So anyone using the word ‘desert’ in this way is using Shakespeare’s language without even realising it. 

The word ‘desert’ can also mean abandoning or running away from a place. A soldier who goes AWOL is said to desert their post, while rats are said to ‘desert a sinking ship’ as a metaphor for people disowning or abandoning a place, person or situation that has become painful, awkward or insupportable. 

When we say a place is deserted, it does not mean it looks like a desert. It means that there are no people around – everyone has departed. 

Finally, a desert is a place that doesn’t get much rain, and is quite barren as a result. 

This is the only meaning that sees ‘desert’ pronounced with the emphasis on the first syllable: dez-ert This makes it a homonym, not a homophone.  Because it’s a place, this is also a noun. 

Fun fact: while the Sahara Desert is hot and sandy, Antarctica is the world’s largest cold desert. 

You can use a sentence to help you remember the three different words that share this spelling. Saying it aloud will help you remember which is which.
Example: The soldier got his just deserts for deserting his post in the hot desert.