An illuminated Christian devotional book, popular in the Middle Ages.

plural of book of hours

Around four to five o'clock in the morning.

(Christianity) One of the canonical hours of prime, terce, sext, nones, and usually compline, the services of which are shorter and considered less important than the three major hours of matins, lauds, and vespers.

plural of half-hour

plural of man of the hour

(time) quarter of an hour; period of time equal to 15 minutes; a quarter.

plural of zero hour

The time at (or very close to) half the next hour of time.

A unit of energy, especially of electrical energy, equal to that done by one megawatt acting for one hour (abbreviation: MWh).