mu·tu·al·i·ty /ˌmyü-chə-'wa-lə-tē/ n: the quality or state of being mutual: as
a: the quality of a contract under which both parties are bound by obligations
b: the state of debts for purposes of set-off under bankruptcy law in which the debts are owed between the same parties standing in the same capacity
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.