tenebrous

Dark, shadowy, or obscure; conveying a sense of gloom or mystery.

• tenebrosity/ˌtɛnɪˈbrɒsɪti/(n)黑暗

• tenebrous depths
• tenebrous atmosphere
• tenebrous forest
• tenebrous passage

1. 1.The tenebrous corridors of the abandoned hospital seemed to swallow the flashlight beam. (shadowy, dark)
2. 2.His novels create a tenebrous world where morality is perpetually ambiguous. (gloomy, obscure)

• murky/ˈmɜːrki/— dark and gloomy
• stygian/ˈstɪdʒiən/— extremely dark, literary
• caliginous/kəˈlɪdʒɪnəs/— misty, dim — very rare

from Latin "tenebrae" (darkness) — the same root gives us "Tenebrae," the Catholic Holy Week service where candles are extinguished one by one