Word family noun effect effectiveness ≠ ineffectiveness adjective effective ≠ ineffective effectual ≠ ineffectual verb effect adverb effectively ≠ ineffectively
From Longman Dictionary of Contemporary Englisheffectualef‧fec‧tu‧al /ɪˈfektʃuəl/ adjective formal EFFECTIVEproducing the result that was wanted or intended SYN effective OPP ineffectualExamples from the Corpus
effectual• Of course, such prior advertisement of a new law is usually necessary for it to be an effectual deterrent.• The plant was boiled in water and the resulting infusion was said to be an effectual diuretic.• I have yet to learn an effectual protective against the midge.• Have denotes an exercise of authority which is effectual, that is, which ensures the realization of the action commanded.• In all, Barratt considered that an effectual trial on the Bonsor Lode could be made for about £1,000. 