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Synonyms for Bagatelle (same or very similar meaning)

WordNet sense 1 (something of little value or significance):
fluff, frippery, frivolity

WordNet sense 2 (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):
bar billiards

From the ODE community, based on WordNetadd/edit