Modifies a noun

• ray: Crepuscular rays may be spotted downward, upward or both; these are upward.

• tenure: Certainly she's as real as anyone else I know - realer in her crepuscular tenure and permanence.

• habit: The Woodcock is an intriguing species, often missed in BTO surveys due to its crepuscular habits.

Modifying Another Word

• generally: They are generally crepuscular ( most active at dusk and dawn ) and nocturnal.