1. [ adjective ] sufficient to produce a result

"a man to whom painting was but another and less effectual way of writing dramas or novels or history"

Related terms: ineffectual effective
2. [ adjective ] exerting or capable of exerting strong physiological or chemical effects

"an effectual vaccine"

Related terms: potent
3. [ adjective ] producing or capable of producing an intended result or having a striking effect
Synonyms: effective efficacious

"an air-cooled motor was more effective than a witch's broomstick for rapid transportation"-LewisMumford "effective teaching methods" "effective steps toward peace"

Related terms: ineffective hard-hitting impelling impressive hard-hitting rough-and-ready powerful useful efficient potent efficacious effectiveness
Similar spelling:   effectually