The Oxford Thesaurus An A-Z Dictionary of Synonyms - activityn.

1) action, movement, motion, vigour, vim, energy, liveliness, bustle: Last week there wasn't much activity in the stock market. 2) pursuit, occupation, vocation, work, function, operation, job, labour, endeavour, enterprise, project, undertaking, venture, interest: What sort of business activity are you engaged in?