bagatelle

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An unimportant or insignificant thing; a trifle.
• noun A short, light piece of verse or music.
• noun A game played on an oblong table with a cue and balls.

from The Century Dictionary.

• noun Specifically, in music, a short and light piece, usually for the piano.
• noun A trifle; a thing of no importance.
• noun A game played on a table having at one end nine holes, into which balls are to be struck with a billiard-cue.

from the GNU version of the Collaborative International Dictionary of English.

• noun A trifle; a thing of no importance.
• noun A game played on an oblong board, having, at one end, cups or arches into or through which balls are to be driven by a rod held in the hand of the player.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A trifle; an unsubstantial thing.
• noun A short piece of literature or of instrumental music, typically light or playful in character.
• noun A game similar to billiards played on an oblong table with pockets or arches at one end only.
• noun Any of several smaller, wooden table top games developed from the original bagatelle in which the pockets are made of pins; also called pin bagatelle, hit-a-pin bagatelle, jaw ball.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun something of little value or significance
• noun a table game in which short cues are used to knock balls into holes that are guarded by wooden pegs; penalties are incurred if the pegs are knocked over
• noun a light piece of music for piano