Wiktionary
a. Having characteristics of a vault
Usage examples of "vaultlike".
She entered a vaultlike room where pale blue light hovered over a stone slab.
The visible sides of a vaultlike container were smooth and unbroken except for a single opening, an inspection hatch two feet square, which had been left open.
Wearing a Level Four biohazard suit, Bauer entered the short corridor between the prep room and the massive, vaultlike door that would allow him to enter the cocoon.
The second shell, the actual kernel, held not only the vaultlike refrigerator where the smallpox was stored, but rows of stainless steel centrifuges and drying and milling machines.
Within minutes, the container that Telegin and Yardeni had died for was being sealed in a stainless-steel box and wheeled to a vaultlike truck, ready to be removed to Moscow's premier research facility, the Serbsky Institute.