From Longman Dictionary of Contemporary Englishsun-upˈsun-up noun [uncountable] old-fashionedTMC sunrise
Examples from the Corpus
sun-up• These are dusk to around 1.30 a.m., and from first glimmer of light to an hour or so after sun-up.• To reach this desolate spot you set off at sun-up and head toward mountain ranges which scarcely ever get closer.• They slipped away just before sun-up.• We have spent two whole days from sun-up till sun-down in rapt conversation.• Probably since sun-up, and he would not stop until it was too dark to work any longer.• It would be dawn soon, then sun-up, and he did not know what he would see. 