Is greeting a noun or verb?

The Word 'greeting' is the present participle, present tense of the verb to greet.

The present participle of the verb is a gerund, a Word that functions as a noun.

The present participle of the verb also functions as an adjective.

EXAMPLES

verb: The host stood by the door greeting the arriving guests.

noun: His greeting was warm and friendly.

adjecitve: He's a one man greeting committee.