Open English Wordnet
Nouns
(n)action, activity, activenessthe state of being active“his sphere of activity”, “he is out of action”
(n)natural process, natural action, action, activitya process existing in or produced by nature (rather than by the intent of human beings)“the action of natural forces”, “volcanic activity”
(n)action, action mechanismthe operating part that transmits power to a mechanism“the piano had a very stiff action”
(n)legal action, action, action at lawa judicial proceeding brought by one party against another; one party prosecutes another for a wrong done or for protection of a right or for prevention of a wrong
(n)actionan act by a government body or supranational organization“recent federal action undermined the segregationist position”, “the United Nations must have the power to propose and organize action without being hobbled by irrelevant issues”, “the Union action of emancipating Southern slaves”
(n)actionIn firearms terminology, the mechanism that handles the ammunition (loads, locks, fires, and extracts the cartridges).“Actions can be categorized in several ways, including single action versus double action, break action versus bolt action, and others.”
Verbs
(v)carry through, accomplish, execute, carry out, action, fulfill, fulfilput in effect“carry out a task”, “execute the decision of the people”, “He actioned the operation”