a. a person who holds a hand so strong that he or she can play a deal without the hand of his or her partner.
b. the hand played by such a person.
2. a person who by preference conducts his or her affairs without the advice or assistance of others: a lone hand in investment circles.
3. a stand or action taken independently: a lone hand in the trade negotiations.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.