Antonyms for

Antonyms of adj efficacious

2 senses of efficacious

Sense 1:
efficacious (vs. inefficacious)

inefficacious (vs. efficacious)

Sense 2:
effective (vs. ineffective), effectual, efficacious © 2001-2013, Demand Media, all rights reserved. The database is based on Word Net a lexical database for the English language. see disclaimer
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