No, jeans are made of twill. twill=denim

A twill jersey is a type of sports uniform that is made of twill. Twill is a woven fabric with a ribbed pattern that is diagonal and parallel.

Twill is a weaving pattern. Cotton used in twill weaving is a staple commodity.

twill is a very rough fabric that comes from elephants.

"Twill", like real velvet, is a type of weave of fiber threads. You could have cotton twill, all right, but you might also have polyester/cotton twill. In theory, you could have twill woven of yak hair.