English dictionary

inefficacious

/,/I/n/E/f/@/'k/eI//S//@/s/

Definitions, examples, synonyms and antonyms from WordNet 3.0.

adjective

lacking the power to produce a desired effect

adj.all

Examples
Laws that are inefficacious in stopping crime.

Antonyms efficacious

Source: WordNet 3.0
Not efficacious; not having power to produce the effect desired; inadequate; incompetent; inefficient; impotent.

adjective

Source: webster1913