The word desert has two different meanings:

1. A large, dry area of land that receives very little rainfall. Most deserts are covered in sand or rock, with few plants and extreme temperatures. The Sahara Desert in Africa is the world's largest hot desert, while Antarctica is technically a cold desert because it gets almost no rain or snow. Despite the harsh conditions, deserts aren't lifeless: camels, lizards, cacti, and many other specially adapted creatures thrive there. When you imagine a desert, you might picture endless sand dunes, blazing sun, and maybe a lone cactus, though real deserts vary widely in appearance.
2. To abandon someone or something when they need you. A soldier who deserts their post leaves without permission. If your best friend deserted you right before a big presentation you were supposed to give together, they left you to face it alone. The word carries a sense of betrayal because it means leaving when you're expected or needed to stay. Notice this meaning is pronounced slightly differently, with the stress on the second syllable (duh-ZERT), while the dry landscape is pronounced with stress on the first syllable (DEZ-urt).