a period of time equal to a twenty-fourth part of a day and night and divided into 60 minutes.
an extra hour of daylight
a point in time.
I wondered if my last hour had come
a fixed period of time for an activity, such as work, use of a building, etc..
shortened working hours
(in the Western Church) a short service of psalms and prayers to be said at a particular time of day, especially in religious communities.
The Liturgy of the Hours is centered on chanting or recitation of the Psalms, using fixed melodic formulas known as psalm tones.
15° of longitude or right ascension (one twenty-fourth part of a circle).
Any object on the same hour circle will have the same right ascension, just as any place on earth on the same meridian of longitude has the same longitude.