noun, plural Prius, Prii [pree-ahy] /ˈpri aɪ/. Trademark.
Origin of Prius
- "In hybrids such as the Toyota Prius, computer software decides when to run the [gasoline] engine, when to run the electric motor and when to recharge the battery. … A full hybrid, such as the Toyota Prius, can provide a fuel economy improvement of 60 percent or more."-Joseph J. Romm and Andrew A. Fran Hybrid Vehicles Gain Traction Scientific American (April 2006)
"that which takes precedence," noun use of Latin neuter of prior "former, earlier" (see prior (adj.)). The hybrid car (with a capital P- ) debuted in 1997 in Japan, 2001 in U.S. and Europe. Name supposedly chosen because the car is a predecessor of new types. Proper plural is said to be Priora, but that is for the adjective.