Is the word bored a noun or adjective?

The Word 'bored' is the past participle, past tense of the verb to bore. The past participle of the verb also functions as an adjective.

Examples:

A large machine bored a tunnel through the earth under the street. (verb)

A bored student could be heard snoozing in the back row. (adjective)

The Word 'bore' is both a noun (bore, bores) and a verb (bore, bores, boring, bored).