n (context|bowling) A set of balls whose results are added together for scoring purposes. Usually two balls, but only one ball in the case of a strike, and three balls in the case of a strike or a spare in the last frame of a game.
n (philately) The outer decoratedportion of a stamp's image, often repeated on several issues although the inner picture may change.
n (film|animation) A division of time on a multimedia timeline, such as 1/30th of a second.
n (Internet) An individually scrollable region of a webpage.