Wiktionary
cavernously
adv. 1 In a cavernous manner; like a cavern. 2 In a cavernous manner; sounding deep, hollow, or echoey.
Usage examples of "cavernously".
The lurid, unearthly glow still hovered in the shadowy chamber, lighting ghostily the dead face of Thugra Khotan, which seemed to grin mirthlessly and cavernously at them.
He looked at Matt Abrahamson's leathery face, at his lantern jaws cavernously and stolidly chewing at a tobacco leaf, and it seemed monstrous to him that the old man should be so unconscious of the black cloud that wrapped them all about.