1. something of little value or significance; trifle
2. a board game in which balls are struck into holes, with pins as obstacles; pinball
3. another name for bar billiards
4. a short light piece of music, esp for piano
She sighed. “Tiens. Your Monsieur Grey has done nothing at all to me, except that kiss which you saw, and perhaps some other careless bagatelles in these last few days, which I do not remember very well. It does not matter much, one way or the other, whether one has performed that particular act or not…And you may stop your foolish laughing, which will only make your shoulder ache.”
Bourne, Joanna. The Spymaster’s Lady,Berkley Sensation, New York, 2008, p. 155.
Definition from http://www.collinsdictionary.com/dictionary/english/bagatelles