Source : Webster's Revised Unabridged Dictionary (1913)

Snowplow \Snow"plow`\, Snowplough \Snow"plough`\, n.
   An implement operating like a plow, but on a larger scale,
   for clearing away the snow from roads, railways, etc.

Source : WordNet®

snowplough
     n : a vehicle used to push snow from roads [syn: {snowplow}]