Webster's Revised Unabridged Dictionary · 1913

Bad

Bad (bad) , imperfect

Bade. [Obsolete] — Dryden

Bad (bad) , adjective

[Probably from Anglo-Saxon baddel hermaphrodite; compare badling effeminate fellow.]

Sometimes used substantively.

Wanting good qualities, whether physical or moral; injurious, hurtful, inconvenient, offensive, painful, unfavorable, or defective, either physically or morally; evil; vicious; wicked; -- the opposite of good; as, a bad man; bad conduct; bad habits; bad soil; bad air; bad health; a bad crop; bad news.
The strong antipathy of good to bad. — Pope