Cre*pus"cu*lar (-k?-l?r), Cre*pus"cu*lous (-l?s), a. [Cf. F. crpusculaire.]
1.
Pertaining to twilight; glimmering; hence, imperfectly clear or luminous.
This semihistorical and crepuscular period.
Sir G. C. Lewis.
2. Zool.
Flying in the twilight or evening, or before sunrise; -- said certain birds and insects.
Others feed only in the twilight, as bats and owls, and are called crepuscular.
Whewell.
© Webster 1913.