D defs.my
Entry 1 sense Webster, 1913

Tenebrous

/tĕn'-əb-rəs/ · Ten·e·brous · IPA /ˈtɛn.ə.bɹəs/
01 a. Dark; gloomy; dusky; tenebrious.
  1. 1.
    Dark; gloomy; dusky; tenebrious.
    “The most dark, tenebrous night.” — J. Hall (1565).
    “The towering and tenebrous boughts of the cypress.” Longfellow.