n. 两小时换班的值班, 夜班

[ noun ]
either of two short watches: from 4-6 pm or 6-8 pm
<noun.time>

Dogwatch \Dog"watch`\, n. (Naut.)
A half watch; a watch of two hours, of which there are two,
the first dogwatch from 4 to 6 o'clock, p. m., and the second
dogwatch from 6 to 8 o'clock, p. m. --Totten.