21-letter words containing p, r, i, s, a, d
- student participation — the extent to which students participate or involve themselves in a class, course, etc
- the stars and stripes — the national flag of the United States of America, consisting of 50 white stars representing the present states on a blue field and seven red and six white horizontal stripes representing the original states
- thermal decomposition — Thermal decomposition is the process in which a chemical species breaks down when its temperature is increased.
- third-party insurance — insurance that compensates for a loss to a party other than the insured for which the insured is liable.
- threshold wage policy — a policy whereby wages are increased in accordance with inflation
- white-crowned sparrow — a North American sparrow, Zonotrichia leucophrys, having black and white stripes on the head.
- wholesale price index — an indicator of price changes in the wholesale market
- xeroderma pigmentosum — a rare inherited disease characterized by sensitivity to ultraviolet light, exposure resulting in lesions and tumors of the skin and eyes.
- yellow lady's-slipper — a showy orchid, Cypripedium calceolus, of eastern North America, having purple-tinged yellow flowers with an inflated lip petal.