Flat
Lightless
Lightless adjective - Being without light or without much light.
Mutual synonyms
Both words in one sentence
-
In The Hobbit it's flat-out stated that the scariest thing Bilbo had to do in his whole adventure was walk down the lightless tunnel to Smaug's lair.
Source: Nothing Is Scarier
Cite this Source
Lightless and Flat. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/flat/lightless
Flat & Lightless. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/flat/lightless>.
Lightless or Flat. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/flat/lightless.
Google Ngram Viewer shows how "flat" and "lightless" have occurred on timeline