1. <physics> The twenty-fourth part of a day; sixty minutes.

2. The time of the day, as expressed in hours and minutes, and indicated by a timepiece; as, what is the hour? at what hour shall we meet?

3. Fixed or appointed time; conjuncture; a particular time or occasion; as, the hour of greatest peril; the man for the hour. "Woman, . . . Mine hour is not yet come." (John II. 4) "This is your hour, and the power of darkness." (Luke xxii. 53)

4. A measure of distance traveled. "Vilvoorden, three hours from Brussels." (J. P. Peters) After hours, after the time appointed for one's regular labour. Canonical hours. See Canonical.

5. <astronomy> Hour angle, a line on which the shadow falls at a given hour; the intersection of an hour circle which the face of the dial. Hour plate, the plate of a timepiece on which the hours are marked; the dial. Sidereal hour, the twenty-fourth part of a sidereal day. Solar hour, the twenty-fourth part of a solar day. The small hours, the early hours of the morning, as one o'clock, two o'clock, etc. To keep good hours, to be regular in going to bed early.

Origin: OE. Hour, our, hore, ure, OF. Hore, ore, ure, F. Heure, L. Hora, fr. Gr, orig, a definite space of time, fixed by natural laws; hence, a season, the time of the day, an hour. See Year, and cf. Horologe, Horoscope.

(01 Mar 1998)