Demsn.

/dɛmz/Etymology: Acronym from the initial letters of Defensively Equipped Merchant Ship.
1943 27 Oct. 266 Defensively equipped merchant ship gunners (‘Dems’) taking a refresher course... A high-angle 4-in. gun being demonstrated to a ‘Dems’ class.
This entry has not yet been fully updated (first published 1972; most recently modified version published online March 2018).