subterrane

1. not comparableSynonym of subterranean.

   The waters stir, / Not as with air, but by some subterrane / And rocking power of the internal world.

   1824, Lord Byron, The Deformed Transformed; a Drama, London: […] J[ohn] and H[enry] L[eigh] Hunt, […], →OCLC, part I, scene I, page 13

   2 more examples

   By this ſecret ſubterrane vault, Zedechias making his ſtealth, recouered (by the helpe of the darke night) the plaines or deſerts of Iericho: […]

   1614, Walter Ralegh [i.e., Walter Raleigh], “Of the Times from the Death of Manasses to the Destruction of Ierusalem”, in The Historie of the World […], London: […] William Stansby for Walter Burre, […], →OCLC, 2nd book, §. VI (The Oppression of Iudæa, and Destruction of Ierusalem by the Chaldæans), page 650

   I watched men in moon suits bury drums of nuclear waste and I thought of the living rocks down there, the subterrane process, the half-life, the atoms that decay to half the original number.

   1997, Don DeLillo, chapter 6, in Underworld, New York, N.Y.: Scribner, →ISBN, page 122

   Synonyms: subterranean

plural subterranes

1. A cave or underground room.

   While these awful scenes were being enacted in the subterranes of the holy inquisition […]

   1857, George W.M. Reynolds, Wagner, The Wehr-Wolf, London: John Dicks