Definition of "acting"

Temporarily assuming the duties or authority of another person when they are unable to do their job.  examples

present participle and gerund of act  examples

(countable, now rare) An action or deed.  quotations

(countable, law) Something done by a party—so called to avoid confusion with the legal senses of deed and action.  examples

(uncountable) Pretending.  examples

(uncountable, drama) The occupation of an actor.  examples