Vulgar or obscene: bad language.
Informal Disobedient or naughty: bad children.
Disagreeable, unpleasant, or disturbing: a bad piece of news.
Unfavorable: bad reviews for the play.
Not fresh; rotten or spoiled: bad meat.
Injurious in effect; detrimental: bad habits.
Not working properly; defective: a bad telephone connection.
Full of or exhibiting faults or errors: bad grammar.
Having no validity; void: passed bad checks.
Being so far behind in repayment as to be considered a loss: bad loans.
Severe; intense: a bad cold.
Being in poor health or in pain: I feel bad today.
Being in poor condition; diseased: bad lungs.
Sorry; regretful: She feels bad about how she treated you.
Slang Very good; great.
Something that is below standard or expectations, as of ethics or decency: weighing the good against the bad.
Usage Problem Badly.
in bad Informal In trouble or disfavor.
my bad Slang Used to acknowledge that one is at fault.
half Informal Reasonably good.
Archaic A past tense of bid.