What does "crepuscular" signify?

The term "crepuscular" specifically refers to things that are related to twilight or the periods of dawn and dusk when the light is dim. It describes animals that are active during these low-light times or phenomena that occur during these transitional times of light. This connection to twilight inherently includes the notion of dimness, making this choice the most accurate definition of "crepuscular." Other contexts may involve aspects of darkness or mystery associated with twilight, but the core definition centers on the traits of being like twilight, hence reinforcing why this choice is the appropriate one.