Meaning of ACTIVITY in English

n. (pl. -ies) 1 a the condition of being active or moving about. b the exertion of energy; vigorous action. 2 (often in pl.) a particular occupation or pursuit (outdoor activities). 3 = RADIOACTIVITY.

[ F activité or LL activitas (as ACTIVE) ]

Concise Oxford English dictionary.      Краткий оксфордский словарь английского языка.