crepuscular

adjective

cre·​pus·​cu·​lar kri-ˈpə-skyə-lər 

1

: of, relating to, or resembling twilight : dim

crepuscular light

the crepuscular sky

2

: occurring or active during twilight

crepuscular insects

crepuscular activity

crepuscular birds

Did you know?

The early Romans had two words for the twilight. Crepusculum was favored by Roman writers for the half-light of evening, just after the sun sets; diluculum was reserved for morning twilight, just before the sun rises—it is related to lucidus, meaning "bright." We didn't embrace either of these Latin nouns as substitutes for our word twilight, but we did form the adjective crepuscular in the 17th century. The word's zoological sense, relating to animals that are most active at twilight, developed in the 19th century.

Examples of crepuscular in a Sentence

Recent Examples on the Web

The study, published last month in the journal Biological Conservation, found that Southland mountain lions became more nocturnal and less crepuscular — i.e., active at dusk or dawn — in popular recreation areas. —Lila Seidman, Los Angeles Times, 7 Dec. 2024

Cats have good night vision, to help with their hunting at dusk, and their crepuscular sleeping habits also explain why many cat owners are woken at the crack of dawn by their pet demanding breakfast. —Nina Turner, Newsweek, 29 Oct. 2024

Recessed domes nod to the moon, light fixtures to celestial bodies, and a palette of purples, silvers, and blues to crepuscular horizons. —Hannah Martin, Architectural Digest, 15 Oct. 2024

The Land at Night Richard Tuohy, Dianna Barrie, 2024, Australia, 16mm, 14m Against a dense, sinister soundtrack of drones, bells, night creatures, and electric hum, flashes of illumination reveal a trembling crepuscular landscape in Richard Tuohy and Dianna Barrie’s The Land at Night. —Ryan Lattanzio, IndieWire, 15 Aug. 2024

Word History

Etymology

borrowed from New Latin crepusculāris, from Latin crepusculum "twilight" + -āris -ar — more at crepuscule

First Known Use

1668, in the meaning defined at sense 1

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Kids Definition

crepuscular

adjective

cre·​pus·​cu·​lar kri-ˈpəs-kyə-lər 

1

: resembling twilight : dim

a faint crepuscular light

2

: occurring or active during twilight

crepuscular insects

Medical Definition

crepuscular

adjective

cre·​pus·​cu·​lar kri-ˈpəs-kyə-lər 

1

: of, relating to, or resembling twilight

crepuscular depths of personality

—William James

2

: active in the twilight

crepuscular animals