crepuscular
adjective
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
Liz O'Connell, MSNBC Newsweek, 21 Oct. 2025
Photograph Of The Year Winners Anti crepuscular rays at Cono de Arita in La Puna, Argentina create an atmospheric optical phenomenon that appears as beams of light converging towards a point opposite the sun in the sky.
—Cecilia Rodriguez, Forbes.com, 6 July 2025
Responding to this, predators have also adopted crepuscular schedules since that is when their prey is more active.
—Ernie Cowan, San Diego Union-Tribune, 6 July 2025
Amazingly, not one species included in the dataset showed an exclusively crepuscular pattern of dawn and dusk activity, as defined in the study, despite many animals being characterized as such in prior research.
—Lauren Leffer, Popular Science, 26 Feb. 2025
See All Example Sentences for crepuscular
Cite this Entry
“Crepuscular.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/crepuscular. Accessed 31 Oct. 2025.
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crepuscular
adjective
Medical Definition
crepuscular
adjective
William James
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