adjective: relating to a statement that functions as an action by the fact of its being uttered.
Notes (from Wordsmith)
Some examples of performative utterances are I promise, I apologize, I bet, I resign, etc. By saying I promise a person actually performs the act of promising.
From Old French parfournir, from par (through) + fournir (to furnish). Earliest documented use: 1922
Usage (from Wordsmith)
“I lost count of the scenes in which Gwen and Peter thrash out the question of whether they should be a couple, and there is a sigh of relief in the cinema when she, deploying what philosophers would call a performative utterance, says simply, ‘I break up with you.’”
Anthony Lane; Trouble Calls; The New Yorker; May 5, 2014.