effectiveness
1. [ noun ] power to be effective; the quality of being able to bring about an effect
Synonyms: effectualness effectuality effectivity
Related terms: ineffectiveness power efficacy incisiveness effective ineffective
2. [ noun ] capacity to produce strong physiological or chemical effects
Synonyms: strength potency
Examples:

: "the toxin's potency" "the strength of the drinks"

Related terms: power impotent potent
Similar spelling:   effectualness
  effectively
  effectivity
  effectuation
  effectuate