hour

hour

1. a period of time equal to 3600 seconds; 1/24th of a calendar day

2. Astronomy an angular measurement of right ascension equal to 15° or a 24th part of the celestial equator

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

hour

Symbol: h.

1. A unit of time equal to 60 minutes, i.e. 1/24 of a day.

2. A unit of angle equal to 15° of arc, i.e. 1/24 of a circle. See right ascension.

Collins Dictionary of Astronomy © Market House Books Ltd, 2006

hour

[au̇r]

(mechanics)

A unit of time equal to 3600 seconds. Abbreviated h; hr.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.