rival (n.) Look up rival at Dictionary.com
1570s, from Latin rivalis "a rival," originally, "one who uses the same stream" (or "one on the opposite side of the stream"), from rivus "brook" (see rivulet). The notion is of the competitiveness of neighbors.
rival (v.) Look up rival at Dictionary.com
c.1600, from rival (n.). Related: Rivaled; rivaling.