Synonyms of unable

Adjective

1. unable (vs. able)

usage: (usually followed by `to') not having the necessary means or skill or know-how; "unable to get to town without a car"; "unable to obtain funds"

2. unable(predicate), incapable (vs. capable)

usage: (usually followed by `to') lacking necessary physical or mental ability; "dyslexics are unable to learn to read adequately"; "the sun was unable to melt enough snow"

3. ineffective, ineffectual, unable, impotent (vs. potent)

usage: lacking in power or forcefulness; "an ineffectual ruler"; "like an unable phoenix in hot ashes"

Definition and meaning of unable (Dictionary)