ENGLISH
REFERENCE

illnesses

n. countable
A2 Elementary US //ˈɪɫnəsɪz// UK //ˈɪlnəsɪz// ill·ness·es

n. periods of being sick or specific diseases that affect your body or mind. You use this word to talk about health problems in general.

n. specific diseases or periods of sickness affecting the body or mind. Plural form of 'illness'; refers to discrete medical conditions or instances of poor health.


SIMPLE

Many common illnesses spread quickly in schools.

CONTEXTUAL

The doctor specializes in treating chronic illnesses that require long-term care and lifestyle changes.

COMPLEX

Public health initiatives aim to reduce the transmission of seasonal illnesses by encouraging regular hand washing and timely vaccinations across the population.

Synonyms
Antonyms
Usage

The plural form is used when referring to different types of diseases or multiple instances of being unwell.

© 2026 English Reference