noun

illness

Translation

illness, sickness, disease

She missed two weeks of work due to illness.

He is recovering from a serious illness.

Mental illness is a serious health issue.

a/an ((adjective)) illness a particular disease He is recovering from a serious illness.

due to illness the state of being ill She missed two weeks of work due to illness.

Synonyms: sickness, disease, ailment; Antonyms: health, wellness

From the adjective 'ill' + the noun-forming suffix '-ness'.

The suffix '-ness' turns an adjective (like 'ill') into a noun (the state of being ill).