To begin doing something or become active suddenly and very quickly.

to begin doing something or become active suddenly and very quickly.

(business) A diagram illustrating the roles of people, teams, etc. in an organization and how they interact with each other and in response to external events.

plural of role activity diagram

Military action undertaken without a formal declaration of war.

(obsolete, gay slang) Taking or preferring to take the insertive role in anal sex.

(obsolete, gay slang) Preferring to give rather than receive fellatio.

A method of learning in which students actively take part in devising the learning process.

Synonym of action plan

Legal proceedings; a lawsuit.