sprocket wheel

from WordNet (r) 3.0 (2006)

sprocket wheel
    n 1: thin wheel with teeth that engage with a chain [syn:
         {sprocket}, {sprocket wheel}]

from The Collaborative International Dictionary of English v.0.48

Sprocket wheel \Sprock"et wheel`\ (spr[o^]k"[e^]t hw[=e]l`).
   [Etymology of sprocket is uncertain.] (Mach.)
   Same as {Chain wheel}.
   [1913 Webster]