slasher

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

• noun One that slashes.
• adjective Characterized by gory violence.

from The Century Dictionary.

• noun One who or that which slashes.
• noun An instrument or appliance of various kinds used in some slashing operation.
• noun In brickmaking, a piece of wrought-iron three feet in length, three inches wide, and three eighths of an inch thick, set in a handle about two and one half feet long and two inches in diameter, used to slash or cut through the clay in all directions with a view to detecting and picking out any small stones that may be found in it.
• noun A machine for sizing, drying, and finishing warp-yarns.
• noun The thrasher or fox-shark.

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

• noun (Textile Manuf.) A machine for applying size to warp yarns.

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

• noun One who slashes.
• noun informal, film A horror movie with graphic blood and violence.
• noun A machine for applying size to warp yarns.

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

• noun someone who slashes another person
• noun a weapon (a sword or dagger) used for slashing