Sunrise is the moment the sun first appears over the horizon, and the light and colour that come with it. Watch the sunrise, at sunrise, before sunrise.
Like sunset it is countable for a particular one and uncountable in fixed phrases: at sunrise takes no article. Sunup is the informal American equivalent, and dawn covers the whole period of growing light rather than the moment. Note the compound sunrise industry, meaning a new and growing one, which is the opposite of a sunset industry — a pair used in economics and easily guessed once you see it.
1nounsunriseThe time when the sun first appears above the horizon.
“They set off before sunrise and got back after dark.”
2nouncoloursThe colours in the sky at that time.
“The sunrise over the water was worth getting up for.”
sunrise is a time of day.
Also accepted in games: dawn
Middle English
sonne-rys
English, today
sunrise
From Middle English sonne-rys, sunne ryse, equivalent to sun + rise. Compare Middle English son risyng, sunne rijsyng, sonne-rysing (“sunrise”) literally “sun rising”.
Etymology from Wiktionary, CC BY-SA
Practised in Nature & Weather, Weather & Seasons