As a verb: It means to have clothing or something else on your body, or to make something deteriorate over time through use.
As a noun: It refers to the act of wearing something, the condition of being worn, or the amount of wear something has.
Therefore, "wear" is not a common noun. Common nouns are general words for people, places, or things (e.g., "dog," "city," "chair").
Here's an example:
* Verb: "She wears a red dress."
* Noun: "The jeans have a lot of wear and tear."
Let me know if you have any more questions!