21-letter words containing p, i, d, g
- pyrenean mountain dog — a large heavily built dog of an ancient breed originally used to protect sheep from wild animals: it has a long thick white coat with a dense ruff
- reading comprehension — a text that students use to help them improve their reading skills, by reading it and answering questions relating to the text. Sometimes used as a test or examination of reading skills. A reading comprehension can be in the student's own or another language
- roodepoort-maraisburg — a city in S Transvaal, in the NE Republic of South Africa.
- sampling distribution — the distribution of a statistic based on all possible random samples that can be drawn from a given population.
- seven-segment display — (electronics) (SSD) A kind of display element consisting of seven independently controllable lines arranged as a rectangular figure eight. A seven-segment display is the simplest device that can display any of the digits zero to nine (and some other characters) by lighting different combinations of lines. They are often seen in electronic calculators or measuring equipment.
- threshold wage policy — a policy whereby wages are increased in accordance with inflation
- whip-and-tongue graft — a graft prepared by cutting both the scion and the stock in a sloping direction and inserting a tongue in the scion into a slit in the stock.
- wildlife photographer — someone that specializes in taking photographs of wild animals, especially in their natural habitats, and plants
- xeroderma pigmentosum — a rare inherited disease characterized by sensitivity to ultraviolet light, exposure resulting in lesions and tumors of the skin and eyes.