retiriĝi

Three pieces and an ending: re- (back), tir- (from tiri, to pull), -iĝ- (become, turn intransitive), -i. Literally, to pull oneself back. An army does it after a battle, a person does it into a quiet room, and a worker does it at the end of a career, and Esperanto uses the one word for all three.

The -iĝ- is not decoration. Retiri would mean to pull something back, with an object: you pull back a hand, a troop, an offer. Retiriĝi means the subject goes back itself, with nobody pulling. That is the entire -ig- against -iĝ- distinction in a single word, and it is the distinction that trips up more learners than any other part of the affix system. Read the rule once, properly, rather than guessing at it for a year.

For the sense of retiring from a job, retiriĝi is the ordinary word and emeritiĝi the formal one. For giving up on something you were trying to do, you want rezigni instead.