subterranean

1. not comparableBelow ground, under the earth, underground.

   And you were in the parking lot / Subterranean by your own design

   1975, Joni Mitchell, “The Boho Dance”, in The Hissing of Summer Lawns

   4 more examples

   Again the bearers took up the coffin, and cold and damp the subterranean air came from the opened vault. The tapers were lowered, and shed a ghastly light on the rows of piled coffins, and the moisture glittering on the walls.

   1834, L[etitia] E[lizabeth] L[andon], chapter XIX, in Francesca Carrara. […], volume III, London: Richard Bentley, […], (successor to Henry Colburn), →OCLC, page 162

   This is a story of north-south connection, and it begins with the fact that late in 1863 the Great Northern Railway completed a subterranean connection from its terminus at King's Cross to the tracks of the Metropolitan enabling the Great Northern to run through to the Met's easterly terminus at Farringdon Street.

   2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, →ISBN, page 52

   The best way to neutralise its [nuclear waste's] threat is to move it into a subterranean vault, of the kind the UK plans to build later this century. Once interred, the waste will be left alone for tens of thousands of years, while its radioactivity cools.

   2022 December 15, Samanth Subramanian, “Dismantling Sellafield: the epic task of shutting down a nuclear site”, in The Guardian

   Today is that most sacred of American holidays. A day when people from all walks of life set aside their differences and focus their undivided attention on the prognostication abilities of a subterranean rodent.

   2025 February 2, Andrew Torgan and Kimberly Richardson, “Start your week smart: Trump tariffs, DC air collision, hostages released, medevac jet crash, FAA system outage”, in CNN

   Synonyms: subterraneous, subterrene, underground, hypogean

2. broadlynot comparableSecret, concealed.

   The subterranean tool of buying rigged opinion polling and media coverage is outlined in remarkable detail in chat exchanges recovered from the cellphone of one of Mr. Kurz’s closest allies and friends, Thomas Schmid.

   2021 October 17, Katrin Bennhold, “Fake Polls and Tabloid Coverage on Demand: The Dark Side of Sebastian Kurz”, in The New York Times, →ISSN

plural subterraneans

1. Someone or something that is subterranean.

   Prue found an ample subterranean, neatly furnished; […]

   1906, Richard Whiteing, chapter X, in Ring in the New, London: Hutchinson & Co. […], →OCLC, page 66

   3 more examples

   [H]e continues Lean like a Hawke or Heron, notwith ſtanding his devouring Appetite: yet it would ſeem that they convey that ſubſtance elſewhere, for theſe Subterraneans eat but little in their Dwellings; […]

   1691, Robert Kirk, “Of the Subterranean Inhabitants”, in Andrew Lang, editor, The Secret Commonwealth of Elves, Fauns, & Fairies: A Study in Folk-Lore & Psychical Research (Bibliothèque de Carabas; VIII), London: […] David Nutt, […], published 1893, →OCLC, page 11

   Whatever elſe the Tauric Cimmerium have been right or wrong called, it is no leſs ſurely a capital of darkneſs, than, near the famous Baths of Baiae, in Campania, the Cimmerium, where the inhabitants were truly Cimmerian; as miners, or other ſubterraneans; who, for good or evil purpoſe, never faced the ſun.

   1782, James Elphinston, “A Comment on the Epigrams of Martial”, in M[arcus] Val[erius] Martial, translated by James Elphinston, The Epigrams of M. Val. Martial, in Twelve Books: with a Comment, London: […] Baker and Galabin, […], →OCLC, book I, part II, page 503, columns 1–2

   Above: a stretch of the walls of the old Cathedral of S. Reparata in the subterraneans of the Duomo.

   1988, Erika Pauli, transl., “Santa Reparata”, in Art and History of Florence, Florence: Casa Editrice Bonechi, page 56