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.

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Other Word Forms

• subeffectiveness
  noun
• supereffectiveness
  noun
• uneffectiveness
  noun

Etymology

Origin of effectiveness

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

Example Sentences

Instead, protective behaviors such as restorative sleep, healthy body weight, effective stress management, avoiding tobacco and maintaining supportive relationships showed a stronger and more lasting connection to younger appearing brains.

From Science Daily • Dec. 15, 2025

“We will work with member states to ensure effective stress tests in the energy sector,” she said.

From Washington Times • Oct. 5, 2022

One of the most effective stress resets involves submerging your face in ice-cold water while holding your breath.

From Washington Post • Sep. 7, 2021

Don't wait until you're upset to find an effective stress neutralizer, says Beverly Flaxington, author of "Self-Talk for a Calmer You" and adjunct professor of leadership and social responsibility at Suffolk University in Boston.

From US News • Sep. 16, 2014

By reason of the contrary rotation of the bar, the effective stress on the lever will be very moderate, while the cut produced will be a clean and quickly performed one.

From Scientific American Supplement, No. 362, December 9, 1882 by Various

Related Words

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