"The ball is round"
I rolled the ball in a perfect round around the table.
we have verandas all round our house
My neighbour invited me round for a drink at Christmas.
In the sentence given, "round" is a noun.
In the sentence "circles are round," the word "round" is an adjective describing the shape of the circles.
a good sentence would be my dog went round and round in circles before his nap
The boxing match was scheduled for a 15 round bout. The man won his bout with cancer.
adverb
use it by saying- how can you use the word ebullient in a sentence?
Can you use the word concluding in a sentence? Done.
How can you use the word infectious in a sentence
You can use the word Truss in a sentence like this.