English Reference
noun

illness

n.
US /ˈɪɫnəs/ UK /ˈɪlnəs/ ill·ness UK spelling illness's, illnesses

  1. 01 A2 Elementary Medicine

    a specific disease or period of being sick.

    a specific instance of disease or a period of sickness. Countable in this sense.

    Simple

    She missed two weeks of school because of a sudden illness.

    In context

    The doctor struggled to diagnose the mysterious illness that had affected several passengers during the long flight.

    Usage

    Often used with adjectives like 'serious', 'minor', or 'chronic'.

    Pitfall
    He has a long illness. He has a chronic illness.

    While 'long' is understandable, 'chronic' or 'prolonged' are the standard adjectives for an illness that lasts a long time.

  2. 02 B1 Intermediate Medicine

    the general state of being unwell or having poor health.

    the general condition of being unhealthy or diseased. Uncountable in this abstract sense.

    Simple

    The company provides insurance to help workers during times of illness.

    In context

    Public health initiatives aim to reduce the burden of illness in urban populations through better sanitation and vaccination programmes.

    Usage

    Often used in formal contexts regarding public health or statistics.

    sicknesspoor health

Usage mental illness


From ill + -ness.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level A2 · Elementary
Frequency Common
Updated