unmannered vs bad-mannered

unmannered and bad-mannered both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unmannered	No	Yes	No	No
bad-mannered	No	Yes	No	No

As adjectives, unmannered and bad-mannered are synonyms defined as:

Other synonyms of unmannered include ill-mannered, rude, unmannerly.

unmannered (adjective)	bad-mannered (adjective)
socially incorrect in behavior	socially incorrect in behavior
without artificiality; natural