noun WYD is an abbreviation for 'What are you doing?' and can be used as a noun to refer to the action or activity someone is currently engaged in.
adverb an adverb modifies a verb, adjective, or other adverb; in this case, 'c'mere' is an adverb indicating a direction or movement toward the speaker
interjection an interjection expresses a strong emotion or sentiment; in this case, 'c'mere' is an informal way of calling someone to come closer