Able to be operated or used / Able to be put into operation; practicable / Able to be treated by surgery

The extent to which a system or device is operable.

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