The Free On-line Dictionary of Computing (30 December 2018):
(Or "vector processor") A computer, or extension
to its arithmetic unit, that is capable of performing
simultaneous computations on elements of an array or table
of data in some number of dimensions.
The IBM AltiVec (the "Velocity Engine" used in the Apple
G4 computers) is a vector processor.
Common uses for array processors include analysis of fluid
dynamics and rotation of 3d objects, as well as data
retrieval, in which elements of a database are scanned
simultaneously. Array processors are very rare now (1998).