'disengage' originates from French, specifically the word 'désengager', where 'des-' (later 'dis-') meant 'undo' and 'engager' meant 'to bind or pledge'.

'disengage' changed from Old/Middle French 'desengagier'/'désengager' and was borrowed into English as 'disengage' in late Middle English/Early Modern English.

Initially, it meant 'to free from a pledge or obligation', but over time it evolved into the broader modern sense of 'to release, detach, or withdraw'.