TENEBRIOUS

tenebrous, tenebrific, tenebrious

(adjective) dark and gloomy; “a tenebrous cave”

Source: WordNet® 3.1

Adjective

tenebrious (comparative more tenebrious, superlative most tenebrious)

Alternative form of tenebrous

Source: Wiktionary

Te*ne"bri*ous, a.

Definition: Tenebrous. Young.

Source: Webster’s Unabridged Dictionary 1913 Edition