Is black an adverb or adjective?

The Word 'blackboard' is a noun, a singular, common, concrete noun; a Word for a thing.

A verb is a Word that describes an action (run, walk, etc), a state of being (exist, stand, etc) or occurrence (happen, become, etc).

A noun is a Word that is used to describe a person (man, lady, teacher, etc), place (home, city, beach, etc) or thing (car, banana, book, etc).