What is the meaning of Effective?

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.

Having no negative coefficients.

approximate; Not describing the fundamental dynamic changes in some system as they happen.

a soldier fit for duty

feminine singular of effectif

vocative masculine singular of effectīvus

Source: wiktionary.org