A pun or play on words.
(RQ:Langley Rhetoric)
{{quote-text|en|year=1984|author=Anthony Burgess|title=Enderby's Dark Lady
{{quote-text|en|year=1997|author=Thomas Pynchon|title=Mason & Dixon
paronomasia
(l)
A figure of speech; pun or play on words which sound alike but have different meanings, paronomasia.