Router \Rout"er\, n. (Carp.)
   (a) A plane made like a spokeshave, for working the inside edges of circular sashes.
   (b) A plane with a hooked tool protruding far below the sole, for smoothing the bottom of a cavity.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Router \Rout"er\, n. (Mach.) A machine with a rapidly revolving vertical spindle and cutter for scooping out the surface of wood or metal, as between and around the engraved parts of an electrotype.

Source: Webster's Revised Unabridged Dictionary (1913)