This is the 11038th most frequent Spanish word.
donut
A sweet, deep-fried pastry typically shaped like a ring.
In this case, 'donut' denotes the same pastry item but is used in the context of a small reward or giveaway.
Al final del partido, todos recibieron un donut como premio.
At the end of the match, everyone received a donut as a prize.
In this sentence, 'donut' is used as a noun referring to a pastry item commonly sold in bakeries.
Hoy compré un donut en la panadería.
Today I bought a donut at the bakery.
Here, 'donut' is again used as a noun, specifically referring to a type of filled pastry item.