the.com/defect

means To abandon one side, cause, or country for another — or, as a noun, a flaw that keeps something from being whole or sound.

from From Latin defectus, 'a failure, a falling away,' built from deficere — 'to fail, to desert, to undo' (de- 'away, down' + facere 'to do/make'). The same Latin root splits into two English lives: the person who defects 'falls away' from a cause, while the defect in an object is a literal falling-short of what it should be. Both senses trace back to that one idea — something undone, something left unfinished.