21-letter words containing s, o, y, e, r
- weinberg-salam theory — electroweak theory.
- william of malmesbury — William of, William of Malmesbury.
- yellow lady's-slipper — a showy orchid, Cypripedium calceolus, of eastern North America, having purple-tinged yellow flowers with an inflated lip petal.
- yellow-fever mosquito — a mosquito, Aedes aegypti, that transmits yellow fever and dengue.
- youth training scheme — (formerly, in Britain) a scheme, run by the Training Agency, to provide vocational training for unemployed 16–17-year-olds