health problem; poor physical health; bad shape; feeling unwell
inferior goods; defective product; defective goods
indigestion; dyspepsia; inability to understand; lacking comprehension; half-baked knowledge
bad girl; juvenile delinquent
bad behavior; misbehavior
bad debt; nonperforming loan
faulty maintenance; poor maintenance; inadequate maintenance
bad inventory; deadstock; dead stock
malnutrition; malnourishment
gang of hoodlums (hooligans); bad company; companion in gang activities
underdevelopment; poor development; maldevelopment; decreased growth; failure to thrive
delinquency; misdeed; misconduct; delinquent behavior
aplastic anemia; aplastic anaemia
blood circulation failure
old sinner; elderly man-about-town; older person who enjoys free and easy lifestyle unfettered by social taboos
nonperforming asset; bad assets; toxic assets
delinquent foreigner; foreign hoodlum
insulator; nonconductor; poor conductor
magnetic strip malfunction (e.g. in a credit card)
malfunction; defective operation; operational failure
defective pixel (on an LCD display)
loose connection; bad contact
getting mixed up with the wrong people; getting into bad company
trouble-shooting; fault analysis