v (intransitive|_|but with prepositional object|by extension) To encounter or meet unexpectedly (literally or figuratively).
v (intransitive|_|but with prepositional object|dated|of flowing water) To reach, to flow into (a body of water).
v (intransitive|_|but with prepositional object) To blend into; to be followed by or adjacent to without there being a clear boundary.