ten·e·brous  (tn-brs) also te·neb·ri·ous (t-nbr-s)
adj.
Dark and gloomy.-adjective
dark; gloomy; obscure.
[Middle English, from Old French tenebreus, from Latin tenebrsus, from tenebrae, darkness.]
Over their heads the towering and tenebrous boughs of the cypress met in a dusky arch. -- Longfellow.