Definition of: hour

(our) noun
1. A space of time equal to one twenty–fourth of a day; sixty minutes; before the general use of timepieces, one twelfth of the interval from sunrise to sunset (called hour of the day), or one twelfth that from sunset to sunrise (called hour of the night).
2. A measure of time as indicated by the sun in relation to the horizon: the sun was two hours high.
3. The point of time indicated by a chronometer, watch, or clock; the time of day.
4. A set, appointed, or definite time; specifically, the time of death.
5. plural Prayers to be repeated at stated times of the day; also, the time for these devotions, or the book containing them.
6. An hour's journey: commonly a league or three miles.
7. A sidereal hour. See SIDEREAL (def. 2).
8. Astron. An angular measure of right ascension or longitude, being 15 degrees or the 24th part of a great circle of the sphere.
—after hours After the prescribed hours for school, business, etc.
—the small hours The early morning hours. ♦ Collateral adjective: horal. [<L hora <Gk. hōra time, period]