caˈvernal,a.rare. [f. L. caverna cavern + -al1.] Pertaining to, or of the nature of, a cavern. 1803G. S. Faber Cabiri II. 266 Hades may be the cavernal space immediately beneath the shell of the earth.1816― Orig. Pagan Idol. I. p. lxx, The two-peaked mountain and sacred cavernal door.