the.com/desertion

means Abandoning a duty, post, or person you were bound to — especially walking out on military service or a family you're obligated to.

from From Latin 'desertus,' past participle of 'deserere' — 'to leave, forsake, abandon,' built from 'de-' (undoing) plus 'serere' ('to join, link together,' the same root that gives us 'series'). So at its core, desertion is the undoing of a join — the snapping of a link that was supposed to hold. The word moved through French into English by the late Middle Ages, and it picked up its grim military weight precisely because armies are one of the few institutions that formalized what happens when you break that link: desertion wasn't just rude, it was punishable, sometimes capitally.