staple gun

from the GNU version of the Collaborative International Dictionary of English.

• noun A device used to drive a heavy staple{8} through multiple objects, so as to fasten them together; it has a spring mechanism which stores force as a lever is pulled by the operator's hand, and the force is released all at once to drive the staple fully into the object to be fastened.

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

• noun A heavy-duty device for driving staples directly into wood or other material.

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

• noun a hand-held machine for driving staples home
• noun a hand-held machine for driving staples home