* It is best to translate this term literally, with a word in the project language that refers to the absence of light. This could also be a term that refers to the darkness of a room with no light or to the time of day when there is no light.
* For the figurative uses, it is also important to keep the image of darkness in contrast to light, as a way to describe evil and deception in contrast to goodness and truth.
* Depending on the context, other ways to translate this could be, "darkness of night" (as opposed to "light of day") or "not seeing anything, like at night" or "evil, like a dark place".