Meaning of E in English

x- [prefix] - used to show that someone is no longer what they were; former (EARLIER)Hundreds of unemployed ex-prisoners could be pushed back towards crime by the closure of job training programmes.Did you know that she'd decided to remarry her ex-husband?A lot of people working as security guards are ex-policemen.

Cambridge English vocab.      Кембриджский английский словарь.