What part of speech is "peerless"?

Peerless is an adjective, which is a word that describes or modifies a noun or pronoun, providing more information about its quality. Adjectives answer questions like what kind, how many, or which one. Peerless is specifically a descriptive adjective that means without peer, without equal, having no rival, unmatched, and superior. It is used to describe nouns, as in peerless beauty, where peerless describes what kind of beauty, or peerless craftsmanship, where it describes the craftsmanship. It comes from the noun peer meaning an equal plus the suffix less meaning without, forming an adjective meaning without equal. As an adjective, it can be used attributively before a noun, as in a peerless performance, or predicatively after a linking verb, as in her performance was peerless. It has comparative and superlative forms that are rarely used, but you could say more peerless or most peerless, though peerless is already absolute. Its adverb form is peerlessly, meaning in a peerless manner, as in she sang peerlessly. The noun form is peerlessness, meaning the state of being without equal. So grammatically, peerless functions as an adjective, always positive, describing something as the best with no equal, and it modifies nouns to emphasize exceptional quality.