Home › Words › U › unmailunmailunmail · verb — to undo the act of mailing; to recover from the postal system before delivery.Definition from Wiktionary (CC BY-SA 3.0).EtymologyFrom un- + mail.verbTo undo the act of mailing; to recover from the postal system before delivery.e.g.“Was it even possible to unmail a letter? She might have to lie, might have to say the letter contained explosives, or some kind of poison. Something extremely illegal.” — 2013, Elizabeth Bass, The Way Back to Happiness:Definitions & examples from Wiktionary (CC BY-SA 3.0).