What is a Speech Act?

@incollection{searle-speechact1965,
   address = {London, UK},
   apice = {SearleSpeechact1965},
   author = {Searle, John},
   booktitle = {Philosophy in America},
   editor = {Black, Maurice},
   pages = {221--239},
   publisher = {Allen and Unwin},
   title = {What is a Speech Act?},
   year = 1965
}