as in effectiveness
the power to produce a desired result
questioned the efficacy of the alarms in actually preventing auto theft
Synonyms & Similar Words
Relevance
Antonyms & Near Antonyms
Example Sentences
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Recent Examples of efficacy
Yet despite the rollback of renewable energy tax credits and a federal government that routinely casts doubt on its efficacy, solar combined with batteries remains by far the fastest-growing energy source in the US, accounting for 91% of new power added to the grid in the first quarter of the year.
—
Tim McDonnell,
semafor.com,
23 June 2026
When using melatonin, the timing and dosage is critical for efficacy and safety.
—
Sally Ibrahim,
The Conversation,
23 June 2026
Dermatologists love EltaMD for the efficacy of the ingredients—this is not your average TikTok-viral product that only looks good on paper.
—
Gina Vaynshteyn,
StyleCaster,
23 June 2026
Many new medicines are required to be stored at specific temperatures to maintain efficacy, UPS said, making healthcare logistics more crucial than before.
—
Laya Neelakandan,
CNBC,
22 June 2026
See All Example Sentences for efficacy
Tim McDonnell,
semafor.com,
23 June 2026
When using melatonin, the timing and dosage is critical for efficacy and safety.
—
Sally Ibrahim,
The Conversation,
23 June 2026
Dermatologists love EltaMD for the efficacy of the ingredients—this is not your average TikTok-viral product that only looks good on paper.
—
Gina Vaynshteyn,
StyleCaster,
23 June 2026
Many new medicines are required to be stored at specific temperatures to maintain efficacy, UPS said, making healthcare logistics more crucial than before.
—
Laya Neelakandan,
CNBC,
22 June 2026
See All Example Sentences for efficacy
Recent Examples of Synonyms for efficacy
Noun
-
As electronic warfare capabilities continue to proliferate, maintaining navigation and mission effectiveness without constant access to satellite signals has become increasingly important.
-
There may be an issue with how the pills dissolve, which could impact their effectiveness.
Noun
-
That’s why operational efficiency matters so much in these conversations.
-
Salazar says those efficiencies cut the typical transaction timeline roughly in half.
Cite this Entry
“Efficacy.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacy. Accessed 30 Jun. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
