deluminate means to extinguish a light; to darken. Lexicurio rates it Sui generis — a strength score of 88 out of 100.
Etymology
From de- + luminate.
verb
- To extinguish a light; to darken.“A modification of the above has a stopcock at the base for controlling the flow of gas into the burner, simultaneously admitting the proper proportion of air to deluminate the flame.”