earnest vs purposeful

earnest is a noun but purposeful is not a noun.

Word	Noun	Adjective	Verb	Adverb
earnest	Yes	Yes	No	No
purposeful	No	Yes	No	No

earnest (noun)	purposeful (noun)
something of value given by one person to another to bind a contract

earnest (adjective)	purposeful (adjective)
not distracted by anything unrelated to the goal	serving as or indicating the existence of a purpose or goal
characterized by a firm and humorless belief in the validity of your opinions	having meaning through having an aim
sincerely earnest