Definition from Wiktionary, the free dictionary
foolery (plural fooleries)
- Foolish behaviour or speech.
- c. 1601, William Shakespeare, Twelfth Night, Act III, Scene 1, 
- Foolery, sir, does walk about the orb like the sun, it shines every where.
1836, Charles Dickens, chapter 9, in Sketches by Boz:
- Tradesmen and clerks, with fashionable novel-reading families, and circulating-library-subscribing daughters, get up small assemblies in humble imitation of Almack’s, and promenade the dingy ‘large room’ of some second-rate hotel with as much complacency as the enviable few who are privileged to exhibit their magnificence in that exclusive haunt of fashion and foolery.
- 1910, John Millington Synge, Deirdre of the Sorrows, in Plays by John M. Synge, London: George Allen & Unwin, 1910, Act I, p. 319, 
- Though you think, maybe, young men can do their fill of foolery and there is none to blame them.
- 1949, George Orwell, Nineteen Eighty-Four, Part Two, Chapter 1, 
- He […] hurried off to the Centre, took part in the solemn foolery of a 'discussion group' […]
- c. 1601, William Shakespeare, Twelfth Night, Act III, Scene 1,