A strongly built room, or vault, where valuables may be stored in safety(noun)
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Use "strongroom" in a sentence
"But they could have started last night, they had started last night for there had been no diving-boat in the Dubh Sgeir boathouse, and reports from the Nantesville's owners had indicated that the strongroom was a fairly antiquated one, not of hardened steel, that could be cut open in a couple of hours with the proper equipment."
"Steeped in sweat - there are no mules or tramways here - they heave their heavy cargoes of ore into a small, dark strongroom before relaxing, cigarettes in hand, chatting and joking."
"By the time they reached the strongroom area almost half the delegates had arrived."