Dictionary entry

Crepuscular

Webster's Dictionary 1913

{ Cre‐pus″cu‐lar (–k?–l?r), Cre‐pus″cu‐lous (–l?s), } a. [Cf. F. crépusculaire.] 1. Pertaining to twilight; glimmering; hence, imperfectly clear or luminous.

This semihistorical and crepuscular period.

Sir G. C. Lewis.

2. (Zoöl.) 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.