A retiree is someone who has stopped doing their paid job, usually because they have reached the age when people leave work. American English loves this word; British English often says “a retired person” or “a pensioner” instead. Though actually, not every retiree is old — some people retire early, and some keep doing a little work afterwards. The word names the person. The time or the state is retirement; the verb is retire. A shy person can be “retiring” in a different sense (quiet, holding back), which has nothing to do with leaving a job.