Here are some examples:
* The soldiers wore their uniforms with pride. (Here, "uniform" refers to the clothing they wore.)
* The school requires all students to wear a uniform. (Here, "uniform" refers to a specific set of clothing.)
It can also be an adjective, meaning "the same" or "consistent":
* The team wore uniform blue shirts. (Here, "uniform" describes the color of the shirts.)
* The workers all received uniform paychecks. (Here, "uniform" describes the consistent amount of pay.)
So, the part of speech for "uniform" depends on its usage in the sentence.