From Longman Dictionary of Contemporary Englishex-conˌex-ˈcon noun [countable] informal a criminal who has been in prison but who is now free
Examples from the Corpus
ex-con• The disclosures have led to firings, assaults and other forms of harassment against the parolees and ex-cons.• Horror stories are rife of ex-cons setting up their own security companies, with all the obvious risks that entails.• At last all seems to be coming together for the ex-con who wants to go straight. 