How the adjective used in onomatopoeia?

No. Onomatopoeia is the adjective used to describe a Word that is a sound. For example: Oink is an onomatopoeia, and so is moo. So the actual Word "onomatopoeia" is not a verb, but the Words that it describes can be. Onomatopoeia could also be a noun. "The cow made a strange onomatopoeia."="The cow made a strange noise"