From WordNet (r) 2.0 (August 2003) [wn]:
hours
n 1: a period of time assigned for work; "they work long hours"
2: an indefinite period of time; "they talked for hours"
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Hours \Hours\, n. pl. [A translation of L. Horae (Gr. ?). See
Hour.] (Myth.)
Goddess of the seasons, or of the hours of the day.
[1913 Webster]
Lo! where the rosy-blosomed Hours,
Fair Venus' train, appear. --Gray.
[1913 Webster]