Emily Dickinson Lexicon

FLUM'MER-Y, n. [W. llymry, from llymyr, harsh, raw, crude, from llym, sharp, severe. In Welsh, a kind of food made of oatmeal steeped in water, until it has turned sour. See Lumber.]

1. A sort of jelly made of flour or meal; pap. Milk and flummery are very fit for children. Locke.
2. In vulgar use, any thing insipid or nothing to the purpose; flattery.