Choose the perfect synonym or antonym for the word

Effective

/ɪˈfektɪv/

Successful in producing a desired or intended result

Synonyms:

It is a simple but effective ruse.'The secret to effective time management is.What makes pomodoro so effective?

originated from Late Latin effectivus, from Latin effectus meaning accomplishment or performance, first appeared in English in the late 14th century

80 mentions per 1 million words

Often

Hint: Frequency according to COCA