effectiveness

American  

[ih-fek-tiv-nis, ee-fek‐] / ɪˈfɛk tɪv nɪs, iˈfɛk‐ /

Rarely effectivity

noun

1. the quality of producing an intended or desired result.

   For maximum effectiveness of your weight loss plan, you need to combine exercise with a healthy diet.

2. the quality of producing a deep or vivid impression.

   We were struck by the evident appeal and effectiveness of these short, dramatic, upbeat video stories.

3. a measure of the success of a vaccine or other pharmaceutical when used in the real world, as opposed to the controlled environment of a clinical trial.

---

Other Word Forms

• subeffectiveness noun
• supereffectiveness noun
• uneffectiveness noun

Etymology

Origin of effectiveness

First recorded in 1600–10; effective ( def. ) + -ness ( def. )

Example Sentences

Few details have been made available, however, and the effectiveness of such unprecedented measures remain to be seen.

From Barron's

We no longer see devastating illnesses like polio and haemophilus meningitis in children, thanks to the effectiveness of herd immunity.

From MarketWatch

Though the sirens have not yet been fully brought online, their effectiveness was illustrated during a recent test run.

From Los Angeles Times

“After multiple waves, the bases lose their effectiveness due to the loss of surface structures and launchers.”

From The Wall Street Journal

The breadth and effectiveness of the Iranian response caught Gulf residents unaware.

From The Wall Street Journal

Related Words

• capability
• efficacy
• efficiency
• potency
• power
• success