1. Of or like twilight; dim: “The gustatory landscape then was dominated by dark, masculine establishments with crepuscular lighting, meat, more meat and puddles of Old World artery-attacking sauces” (Karen Heller).
a. Active primarily at dawn or dusk or both. Used of animals.
b. Occurring at dawn or dusk or both: crepuscular foraging; a crepuscular stroll through the park.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.