What is the X in X-mas?
"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.