English

ill adjective definition in Being ill topic from the Oxford Advanced Learner's Dictionary

ill

 adjective: Being ill topic
(especially British English) (usually North American English sick) [not usually before noun] suffering from an illness or disease; not feeling well Her father is seriously ill in St Luke's hospital. She was taken ill suddenly. We both started to feel ill shortly after the meal. Uncle Harry is terminally ill with cancer (= he will die from his illness). the mentally ill (= people with a mental illness) (formal) He fell ill and died soon after.