Of or like twilight; dim: "the period's crepuscular charm and a waning of the intense francophilia that used to shape the art market” ( Wall Street Journal).
Zoology Becoming active at twilight or before sunrise, as do bats and certain insects and birds.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.