Oxford Advanced American Dictionary

Definition of ill adverb from the Oxford Advanced Learner's Dictionary

ill

adverb
ill pronunciation English ɪl ill pronunciation American ɪl
 
1 (especially in compounds) badly or in an unpleasant wayThe animals had been grossly ill-treated.2 (formal) badly; not in an acceptable wayThey live in an area ill served by public transport.3 (formal) only with difficultyWe're wasting valuable time, time we can ill afford.I can ill afford the time or the money for a holiday.
Idioms

speak/think ill of somebody

(formal) to say or think bad things about somebodyDon't speak ill of the dead.