Meaning of “ill” - Learner’s Dictionary

ill

adjective uk us /ɪl/
NOT HEALTHY

A2 not feeling well, or suffering from a disease:

Her mother was too ill to travel.
Mark had been feeling ill for a couple of days.
BAD [ always before noun ] formal

bad:

ill health
He suffered no ill effects from his fall.
→ See also ill at ease

(Definition of “ill adjective” from the Cambridge Learner’s Dictionary © Cambridge University Press)