The property of being effective, of achieving results. / The capacity or potential for achieving results. / The degree to which something achieves results.

Having the power to produce a required effect or effects. / Producing a decided or decisive effect. / Efficient, serviceable, or operative, available for useful work. / Actually in effect.

(military) a soldier fit for duty

present participle of effect

Causative, effective.

with more or less the meaning of

plural of effectiveness

plural of effecter

(psychology) effective interaction with one's environment

Creation; a doing.