crepuscular
adjective uk/krɪˈpʌs.kjə.lər/ us/krɪˈpʌs.kjə.lɚ/
literary拂晓的;黄昏的;昏暗的
relating to or like the time of day just before the sun goes down, when the light is not bright
biology specialized （动物）晨昏活动型的
(of animals) active or appearing at the time of day just before the sun goes down, or just after the sun rises, when the light is not bright
Deer are crepuscular, meaning that they are most active at dawn and at dusk. 鹿是晨昏活动型动物，即它们在凌晨或黄昏最活跃。