What is the definition of the word "tenebrous"?

The word "tenebrous," an
adjective (pronounced ten'-uh-brus) has origins in Middle English and its first
documented use was in the 15th century in England and/or France. It is derived from the
Latin words tenebrae and tenebrosus. There are
several different yet similar definitions of the
word.

• In one form it means "cut off from
  light." 


• Another form is "difficult to
  understand."


• A third version is "a state of gloom or
  shadows"

Other forms of the word
include tenebrosity (noun), tenebrousness (noun), and tenebriousness (noun). Synonyms
include dark, gloomy, murky, obscure, somber, black, shadowy,
lightless.