IPA: /ˈwɔːdruːm/
KK: /ˈwɔrdˌrum/
A room on a warship where commissioned officers eat and relax, and which serves as their living quarters, excluding the captain.
The officers gathered in the wardroom to discuss the mission plans over dinner.
Wardroom → The word is formed from "ward" (from Old English *weard*, meaning to guard or protect) and "room" (from Old English *rum*, meaning space or area). A wardroom is a space designated for officers on a ship, where they can gather and conduct their duties, thus serving as a protective area for their activities.
Think of a 'guarding' space ('ward') where officers gather ('room') — that's what a wardroom is.