uncollectible, wanting, imperfect, abnormal, better, sorry, big, bad, speculative, forged, faulty, regretful, spoilt, high-risk, nonfunctional, excess, lacking, risky, malfunctioning, unfit, tough.
blemished (part of speech: adjective)
erroneous (part of speech: adjective)
bad (part of speech: adjective)
imperfect (part of speech: adjective)
unintellectual (part of speech: adjective)
impure (part of speech: adjective)