Notice how I've pronounced the adjective "desolate" ("DESS uh lut"). Change the pronunciation of that last syllable from "lut" to "late" and you have a verb: to desolate ("DESS uh late"). To desolate a place is to empty it, to wreck it, to make it lonely and blank: to wipe out all the people or living things. And if you desolate people, you totally wreck their hearts, leaving them feeling empty and alone.
That brings us to "desolation," which most often means "emptiness, blankness, or loneliness in a place," but can also mean "an emptiness in your heart." If you feel desolated, or if you wallow in desolation, that means you feel lonely, alone, and empty.
And, "desolation" can mean "total destruction: the act of wiping out everything, leaving everything empty and blank." Think of a planet with no life on it: a desolate planet. Maybe there was never any life there at all, but maybe it was once full of life that was desolated by something. Say, a meteor. That actually happened on our planet! Back when the dinosaurs ruled the earth, a meteor hit, which desolated the planet: it blocked out the sunlight, which stopped all the plants from growing and wiped out most life on the surface of the planet, leaving it desolate.
If you've seen the movie The Hobbit: The Desolation of Smaug, then you might remember how the dragon Smaug desolated the city of Dale. Smaug smashed, burned, or killed everything and everyone in the entire city. He desolated it. In the image below, you can see the desolate remains of the city.
By the way, that prefix "de-" is sneaky! It doesn't always mean "totally." Sometimes it means "away or off" (like in the word "defend"), or "down" (like in "depress"), or even "not or undo" (like in "declassify").
Make a flash card:
You can write your own definition and choose your own picture, or copy mine.
barren and empty, in a sad, lonely way
Write your own sentence!
You can use either of the two ideas I'll suggest, or you can invent your own. Include as much detail as you can!