Words

flap, v.

THE WORLD divides into adherents of Quentin Crisp and of Florence Nightingale. His dust accumulates while her Notes on Nursing (1859) asserts: "Flapping, by way of cleaning, is only admissible in the case of pictures . . . The only way I know to remove dust is to wipe everything with a damp cloth."

The OED cites her views on slop-pails and old wallpaper (both unhygienic), but overlooks this. Perhaps she echoes an 18th-century expression unknown to Johnson, who thought flap ("to ply the wings with noise") was Anglo- Saxon. More likely it is - as in Dutch and German - 14th-century onomatopoeia. Jonathan Green's endlessly educative Slang gives many more meanings, including a link between Twenties flappers and a 19th-century Northumberland indecency.