Emily Dickinson Lexicon

CRE-PUS'CLE, or CRE-PUSC'ULE, n. [L. crepusculum, from crepo or its root, a little burst or break of light, or broken light. Creperus is from the same root.]

Twilight; the light of the morning from the first dawn to sunrise, and of the evening from sunset to darkness. It is occasioned by the refraction of the sun's rays.