| Definition -
A speech act that either asserts, suggests, demands, warns, promises, vows, or requests.
For example, if when dining you say "Please, pass me the catsup?", you are:
(1) performing the illocutionary act of requesting catsup
(2) performing the locutionary act of saying a sentence, and
(3) performing the perlocutionary act of causing somebody to pass you the catsup.
Etymology - The term was introduced by the philosopher John L. Austin.