IPA: //ˈɡʌnruːm//
KK: /gʌnrum/
A room on a British warship where midshipmen and junior officers stay or work.
The midshipmen gathered in the gunroom to discuss their duties for the day.
Gunroom → The word is formed from "gun" (from Middle English *gunne*, meaning a type of firearm) and "room" (from Old English *rum*, meaning space or area). A gunroom is a designated space for storing or using guns.
Think of a 'space' ('room') specifically for 'firearms' ('gun') — that's what a gunroom is.