Synonyms of inefficacy

2 Syllables
bringdown, weakness
3 Syllables
helplessness, inaptness, skimpiness, ineptness, faultiness, feebleness
4 Syllables
uselessness, powerlessness, infirmity, impotence, disappointment, defalcation
5 Syllables
incompleteness, inadequacy, incompetency, inaptitude, ineffectualness, inutility, defectiveness, inability, inadequacies
6 Syllables
incapability, ineffectiveness, incapacitation