DictionaryAI

activity

noun
Sayak-TIV-i-tee/ækˈtɪv.ɪ.ti/UK/ækˈtɪv.ɪ.tiː/

Pluralactivities

5 meanings of activity

Practice

  1. 1
    nouncountable
    Something you do, especially for work, learning, exercise, or fun.

    Like one job on your list of things to do.

    Cleaning the kitchen is a tiring activity.

    The class tried several new activities during the lesson.

    UsageSay you do or take part in an activity.

    Similarpursuit, pastime, task

  2. 2
    amount of movementnoununcountable
    The state of being busy and moving around a lot.

    Like a beehive that is always busy and moving.

    There was a lot of activity in the market this morning.

    After the new medicine, the patient showed more activity.

    UsageSay there is a lot of activity, or a place is busy with activity.

    Similaraction, movement, bustle, motion

    Oppositeinactivity, idleness, stillness

  3. 3
    chemistrynouncountable or uncountable
    How easily a substance reacts with other substances.

    Like how dry wood catches fire easily but wet wood hardly burns.

    Gold has very low activity, which is why it stays shiny for centuries.

    The metal's high activity made it react fast with acid.

    Similarreactivity

    Oppositeinertness

Less common meanings

  1. 4
    decay ratenouncountable or uncountable
    How many times a radioactive material breaks down each second.

    Like counting how many popcorn kernels pop each second in a hot pan.

    The Geiger counter showed the sample's activity dropping a little every day.

    Doctors measured the activity of the tracer in the patient's blood.

    Similarradioactivity

    Note
  2. 5
    noun
    In grammar, the type of verb or phrase that describes something going on over time with no set end.

Practice

Can you tell the meanings of activity apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.

Origin

From Latin activitas, related to the word 'active'.

Checked 31 Oct 2026 · 2 facts