fourhanded

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

• adjective Games Involving or requiring four players.
• adjective Designed for four hands, as a piano duet.

from The Century Dictionary.

• Having four hands; quadrumanous.
• Done or played by four hands, or by four persons: as, a four-handed piece for the piano; a four-handed game of cards.

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

• adjective Having four hands; quadrumanous.
• adjective Requiring four “hands” or players.

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

• adjective Having four hands; quadrumanous.
• adjective Requiring four players.

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

• adjective (of card games) involving or requiring four players