Antonyms of adj able

4 senses of able

Sense 1
able (vs. unable) -- ((usually followed by `to') having the necessary means or skill or know-how or authority to do something; "able to swim"; "she was able to program her computer"; "we were at last able to buy a car"; "able to get a grant for the project")

unable (vs. able) -- ((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")

Sense 2
able, capable -- (have the skills and qualifications to do things well; "able teachers"; "a capable administrator"; "children as young as 14 can be extremely capable and dependable")

INDIRECT (VIA competent) -> incompetent -- (not qualified or suited for a purpose; "an incompetent secret service"; "the filming was hopeless incompetent")

Sense 3
able -- (having inherent physical or mental ability or capacity; "able to learn"; "human beings are able to walk on two feet"; "Superman is able to leap tall buildings")

INDIRECT (VIA capable) -> incapable -- ((followed by `of') lacking capacity or ability; "incapable of carrying a tune"; "he is incapable of understanding the matter"; "incapable of doing the work")

Sense 4
able, able-bodied -- (having a strong healthy body; "an able seaman"; "every able-bodied young man served in the army")

INDIRECT (VIA fit) -> unfit -- (not in good physical or mental condition; out of condition; "fat and very unfit"; "certified as unfit for army service"; "drunk and unfit for service")

Similarity of adj able

4 senses of able

Sense 1
able (vs. unable) -- ((usually followed by `to') having the necessary means or skill or know-how or authority to do something; "able to swim"; "she was able to program her computer"; "we were at last able to buy a car"; "able to get a grant for the project")

Sense 2
able, capable -- (have the skills and qualifications to do things well; "able teachers"; "a capable administrator"; "children as young as 14 can be extremely capable and dependable")
       => competent (vs. incompetent) -- (properly or sufficiently qualified or capable or efficient; "a competent typist")

Sense 3
able -- (having inherent physical or mental ability or capacity; "able to learn"; "human beings are able to walk on two feet"; "Superman is able to leap tall buildings")
       => capable (vs. incapable) -- ((usually followed by `of') having capacity or ability; "capable of winning"; "capable of hard work"; "capable of walking on two feet")

Sense 4
able, able-bodied -- (having a strong healthy body; "an able seaman"; "every able-bodied young man served in the army")
       => fit (vs. unfit) -- (physically and mentally sound or healthy; "felt relaxed and fit after their holiday"; "keeps fit with diet and exercise")