lawn mower

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A machine with a rotating blade for cutting grass.

from The Century Dictionary.

• noun One who or that which mows a lawn; specifically, a machine, either pushed over the ground by hand or drawn by a horse, according to its size, for cutting the grass on a lawn.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any form of machine, having rotating blades, used to cut grass.
• noun A person who mows lawns using a lawnmower.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun garden tool for mowing grass on lawns