efficacious
2 synonyms and 1 antonym for efficacious, grouped by meaning and by how common each one is.
Adj — Producing the effect that is wanted.
Synonyms
Everyday swaps
Common words most readers know — safe in any writing.
Rare, literary or technical
Precise, but they will stand out — check the sense before using one.
Antonyms
Etymology
From Old French efficacieux (the source of -acious), from Latin efficāx ("efficacious") plus -ous, from efficere ("to effect, to accomplish"); compare effect.
Full origin of efficacious →