21-letter words containing a, c, e, t, y
- uncertainty principle — the principle of quantum mechanics, formulated by Heisenberg, that the accurate measurement of one of two related, observable quantities, as position and momentum or energy and time, produces uncertainties in the measurement of the other, such that the product of the uncertainties of both quantities is equal to or greater than h/ 2 π, where h equals Planck's constant.
- university of iceland — (body, education) The Home of Fjolnir.
- vertically challenged — short in stature.
- veterinary technician — a veterinarian’s assistant, trained to provide medical care for animals, as performing diagnostic tests or administering vaccines and medication.
- voice-stress analyzer — a machine purported to detect stress in a human voice and to ascertain a person's truthfulness.
- water-vascular system — a system of closed, fluid-filled tubes and ducts of echinoderms used in clinging, locomotion, feeding, and respiration.
- west university place — a city in SE Texas.
- youth training scheme — (formerly, in Britain) a scheme, run by the Training Agency, to provide vocational training for unemployed 16–17-year-olds