earnest vs businesslike

earnest is a noun but businesslike is not a noun.

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

As adjectives, earnest and businesslike are synonyms defined as:

earnest and businesslike: not distracted by anything unrelated to the goal

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

earnest (adjective)	businesslike (adjective)
not distracted by anything unrelated to the goal	exhibiting methodical and systematic characteristics that would be useful in business
characterized by a firm and humorless belief in the validity of your opinions	not distracted by anything unrelated to the goal
sincerely earnest