Dictionary Check: efficacious

"efficacious" is a valid word!

Scrabble 21 points
Words with Friends 24 points

Definition

adjective

marked by qualities giving the power to produce an intended effect

Example: "written propaganda is less efficacious than the habits and prejudices … of the readers"
Antonyms:
adjective

producing or capable of producing an intended result or having a striking effect

Example: "an air-cooled motor was more effective than a witch's broomstick for rapid long-distance transportation"
Synonyms:

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