21-letter words containing p, a, y, r, o
- ulster unionist party — a Northern Irish political party advocating the maintenance of union with the UK
- x-ray crystallography — the determination of the structure of a crystal by the use of x-ray diffraction.
- yellow lady's-slipper — a showy orchid, Cypripedium calceolus, of eastern North America, having purple-tinged yellow flowers with an inflated lip petal.
- yellow-rumped warbler — a common North American wood warbler, Dendroica coronata, having yellow spots on the rump, crown, and sides, including a white-throated eastern subspecies (myrtle warbler) and a yellow-throated western subspecies (Audubon's warbler)