- the state or quality of being active
- lively action or movement
- any specific deed, action, pursuit, etc: recreational activities
- the number of disintegrations of a radioactive substance in a given unit of time, usually expressed in curies or disintegrations per second
- the capacity of a substance to undergo chemical change
WordReference Random House Learner's Dictionary of American English © 2026
ac•tiv•i•ty /ækˈtɪvɪti/USA pronunciation
n., pl. -ties.
WordReference Random House Unabridged Dictionary of American English © 2026- [uncountable] the state or quality of being active or lively.
- a specific deed, action, or function:[countable]social activities.
ac•tiv•i•ty
(ak tiv′i tē),USA pronunciation n., pl. -ties.
- the state or quality of being active:There was not much activity in the stock market today. He doesn't have enough physical activity in his life.
- a specific deed, action, function, or sphere of action:social activities.
- work, esp. in elementary grades at school, that involves direct experience by the student rather than textbook study.
- energetic activity;
animation;
liveliness. - a use of energy or force;
an active movement or operation. - normal mental or bodily power, function, or process.
- Chemistry[Physical Chem.]the capacity of a substance to react, corrected for the loss of reactivity due to the interaction of its constituents.
- Physics
- the number of atoms of a radioactive substance that disintegrate per unit of time, usually expressed in curies.
- radioactivity.
- an organizational unit or the function it performs.
- Medieval Latin āctīvitās. See active, -ity
- Middle French)
- (1520–30
Collins Concise English Dictionary © HarperCollins Publishers::
activity /ækˈtɪvɪtɪ/ n ( pl -ties)
'activity' also found in these entries (note: many are not synonyms or translations):
abuzz
- acrobatics
- act of God
- action
- ado
- adventure
- aggravated trespass
- aggression
- allergy
- alpha rhythm
- amateur
- anorak
- après-ski
- arena
- aristocracy
- art
- at
- attention deficit disorder
- away
- background
- bestiality
- beta-blocker
- beta rhythm
- bioassay
- biofeedback
- biohacking
- blood
- boom
- bore
- brain fingerprinting
- brainstorm
- break even
- breccia
- bursty
- business
- bustle
- busy
- catch up
- centre
- charter
- cinnabar
- circle
- climacteric
- cockatoo
- coenzyme
- commerce
- complicit
- condemn
- conscious
- ability