noun

1. A soldier fit for duty

adjective

1. Having the power to produce a required effect or effects.

   “The pill is an effective method of birth control.”

2. Producing a decided or decisive effect.

   “The president delivered an effective speech!”

3. Efficient, serviceable, or operative, available for useful work.

   “How long does it take to make a bunch of civilians an effective military force?”

Synonyms: efficacious