Merriam-Webster Collegiate Dictionary - multiplicity

 noun  (plural -ties)  Etymology: Middle English, from Middle French multiplicite, from Late Latin multiplicitat-, multiplicitas, from Latin multiplic-, multiplex  Date: 15th century  1.  a. the quality or state of being multiple or various  b. the number of components in a system (as a multiplet or a group of energy levels)  2. a great number  3. the number of times a root of an equation or zero of a function occurs when there is more than one root or zero the ~ of x = 2 for the equation (x - 2)3 = 0 is 3