Pronunciation: (ku-myOO'tu-tiv, kom'yu-tā"tiv), [key]
1. of or pertaining to commutation, exchange, substitution, or interchange.
a. (of a binary operation) having the property that one term operating on a second is equal to the second operating on the first, as a × b = b × a.
b. having reference to this property: commutative law for multiplication.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.