subterraneous

From Latin subterraneus.

subterraneous (not comparable)

1. Subterranean.
   • 1764, “Onuphrio Muralto”, chapter I, in William Marshal [pseudonym; Horace Walpole], transl., The Castle of Otranto, […], Dublin: […] J. Hoey, […], published 1765, →OCLC:

     [S]he recollected a subterraneous passage which led from the vaults of the castle to the church of saint Nicholas.

   • 1836 October, Washington Irving, chapter XXVI, in Astoria, or Anecdotes of an Enterprise beyond the Rocky Mountains. […], volume I, Philadelphia, Pa.: [Henry Charles] Carey, [Isaac] Lea, & Blanchard, →OCLC, page 254:

     The Indians of the Orellanna, also, tell of horrible noises heard occasionally in the Paraguaxo, […] Others have endeavored to account for these discharges of "mountain artillery" on humbler principles; attributing them […] to the disengagement of hydrogen, produced by subterraneous beds of coal in a state of ignition.

   • 1851 November 14, Herman Melville, Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, →OCLC:

     A low rumbling sound was heard; a subterraneous hum; and then all held their breaths; as bedraggled with trailing ropes, and harpoons, and lances, a vast form shot lengthwise, but obliquely from the sea.

   • 1944 September and October, Charles E. Lee, “An Ancient Underground Railway”, in Railway Magazine, page 275:

     The 3-mile underground railway—or "subterraneous wagonway"—was begun about 1770 by Christopher Bedlington, and was therefore commonly known as Kitty's Drift.

Before 1830, this word was more common in print use than subterranean. However, in contemporary English the word is used less than 1% as often as subterranean.

• subterraneousness