person who has left a job; former employee; unemployed person
Refers to someone who has resigned, retired, or been laid off. Often used in economic or labor contexts.
Support for re-employment of people who have left their jobs is important.
As an unemployed person, he goes to Hello Work.
失業者 means 'unemployed person' and emphasizes the state of being without work and seeking employment, whereas 離職者 focuses on the fact of having left a previous job, regardless of current employment status.
Compound of 離職 (りしょく, 'leaving a job') + 者 (しゃ, 'person').