Word a Day
efficacy
What does efficacy mean?
efficacy (noun): a degree of ability to produce a desired effect; effectiveness.
Definition: Wiktionary, CC BY-SA 4.0.
How do you use efficacy in a sentence?
- This practice is of dubious efficacy. (Tatoeba sentence #6049469 by mailohilohi, CC BY 2.0 FR)
Where does efficacy come from?
From Old French efficace, from Late Latin efficācia (“efficacy”) (whence -acy), from efficāx (“efficacious”).
Etymology: Wiktionary, CC BY-SA 4.0.
Words related to efficacy
From Princeton WordNet 3.1.
Test yourself: do you know “efficacy”?
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What does “efficacy” mean?
an advance or movement made from one foot to the other; a pace
Not quite: that's what step means.
the front opening of a creature through which food is ingested
Not quite: that's what mouth means.
something that is representative of all such things in a group
Not quite: that's what example means.
a degree of ability to produce a desired effect; effectiveness
Right! That's what “efficacy” means.
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