Definition from Wiktionary, the free dictionary
Welsh llymru, a jelly derived from oatmeal
flummery (plural flummeries)
- A custard; any of several bland, gelatinous foodstuffs, usually made from stewed fruit and thickened with oatmeal, cornstarch or flour
- empty or meaningless talk
- deceptive or blustering speech; bullshit
- 1940: Rex Stout, Over My Dead Body - "Pfui! This is flummery!"
- This is the twentieth century, for what it’s worth. It’s not the age of reason, or even the nineteenth century, it’s the era of flummery, and the day of the devious approach. Reason’s gone into the backrooms where it works to devise means by which people can be induced to emote in the desired direction.” 
- ^ John Wyndham, The Trouble With Lichen (1960), Penguin Books. pg. 91.