(mathematics, logic) An operation on logical values that changes true to false, and false to true.

In an operative manner.

plural of operativeness

(uncountable) The state or quality of being operative. / (countable) The result or product of being operative.

plural of oper

(Internet) A network operator on IRC.

Obsolete form of operose.

The act of operating or working; operation.

operativeness

Abbreviation of Old Persian.