This is the etymology they provided:
"Tenebrous" means "obscure" or "murky," but there's nothing unclear about its history. Etymologists know that the word derives from the Latin noun "tenebrae," which means "darkness." "Tenebrous" has been used in English since the 15th century, and in the 20th century it was joined by some interesting relations. "Tenebrionid" is the name of a nocturnal beetle that is usually dark-colored and is also called a "darkling beetle." "Tenebrism" refers to a style of painting -- associated with the Italian painter Caravaggio -- in which most of the figures are engulfed in shadow but some are dramatically illuminated by concentrated light.
This reminded me of a passage in 1 Corinthians:
For now we see in a mirror dimly, but then face to face; now I know in part, but then I will know fully just as I also have been fully known. (1 Corinthians 13:12)
Instead of walking in darkness and seeing dimly may we instead walk in the light. Here are some verses that speak of "in the light":
For You have delivered my soul from death, Indeed my feet from stumbling, So that I may walk before God In the light of the living. (Psalms 56:13)
How blessed are the people who know the joyful sound! O LORD, they walk in the light of Your countenance. (Psalms 89:15)
You have placed our iniquities before You, Our secret sins in the light of Your presence. (Psalms 90:8)
In the light of a king's face is life, And his favor is like a cloud with the spring rain. (Proverbs 16:15)
Come, house of Jacob, and let us walk in the light of the LORD. (Isaiah 2:5)
"What I tell you in the darkness, speak in the light; and what you hear whispered in your ear, proclaim upon the housetops. (Matthew 10:27)
"Accordingly, whatever you have said in the dark will be heard in the light, and what you have whispered in the inner rooms will be proclaimed upon the housetops. (Luke 12:3)
"While you have the Light, believe in the Light, so that you may become sons of Light." These things Jesus spoke, and He went away and hid Himself from them. (John 12:36)
"...but if we walk in the Light as He Himself is in the Light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin." (1 John 1:7)
The one who says he is in the Light and yet hates his brother is in the darkness until now. The one who loves his brother abides in the Light and there is no cause for stumbling in him. (1 John 2:9-10)
May those who have faith in the Most High always walk in the light of His presence. Amen.