performative utterance

listen to the pronunciation of performative utterance
English - English
A sentence or other linguistic expression which, when expressed in an appropriate context, actually does or accomplishes something

Famous examples of performative utterances are I now pronounce you husband and wife (when uttered by the authorized officiator during a marriage ceremony) or You're fired! (when exclaimed by an employer terminating a person's employment).

A performative utterance
performative