(a)badhaving undesirable or negative qualities“a bad report card”, “his sloppy appearance made a bad impression”, “a bad little boy”, “clothes in bad shape”, “a bad cut”, “bad luck”, “the news was very bad”, “the reviews were bad”, “the pay is bad”, “it was a bad light for reading”, “the movie was a bad choice”
(a)regretful, sorry, badfeeling or expressing regret or sorrow or a sense of loss over something done or undone“felt regretful over his vanished youth”, “regretful over mistakes she had made”, “he felt bad about breaking the vase”
(s)bad, toughfeeling physical discomfort or pain (`tough' is occasionally used colloquially for `bad')“my throat feels bad”, “she felt bad all over”, “he was feeling tough after a restless night”
(s)bad, risky, high-risk, speculativenot financially safe or secure“a bad investment”, “high risk investments”, “anything that promises to pay too much can't help being risky”, “speculative business enterprises”
(r)badly, badwith great intensity (`bad' is a nonstandard variant for `badly')“the injury hurt badly”, “the buildings were badly shaken”, “it hurts bad”, “we need water bad”
(r)badly, badvery much; strongly“I wanted it badly enough to work hard for it”, “the cables had sagged badly”, “they were badly in need of help”, “he wants a bicycle so bad he can taste it”