noun
: a function of the sum of two or more variables that is equal to a sum each term of which is the same function of one of the variables : any function F such that F(u+v)= F(u)+F(v)
noun
: a function of the sum of two or more variables that is equal to a sum each term of which is the same function of one of the variables : any function F such that F(u+v)= F(u)+F(v)
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012