Crepusculum
The Century Dictionary and Cyclopedia
noun.
Twilight.
Wiktionary, Creative Commons Attribution/Share-Alike License
noun.
crepuscule
;
twilight
;
dusk
Word Usage
"Dr.F. also mentions, "that cocks began to crow during the darkness of the eclipse of the sun, Sept. 4, 1820; and it seems that _crepusculum_ (or twilight) is the sort of light in which they crow most.""