ex-convict; former prisoner
A somewhat formal or literary term for a person who has served a prison sentence. In everyday speech, 前科者 or 元受刑者 may be more common.
There are systems to support the reintegration of ex-convicts into society.
He got a job while hiding the fact that he was an ex-convict.
元受刑者 is a neutral, descriptive term for a former inmate, often used in official contexts, whereas 刑余者 carries a slightly literary or dated tone.
Compound of 刑 (kei, 'punishment, penalty') + 余 (yo, 'after, remaining') + 者 (sha, 'person'). Literally 'person after punishment', referring to someone who has completed a prison term.