Antonyms of adj attainable

1 sense of attainable

Sense 1
attainable, come-at-able -- (capable of being attained or accomplished; "choose an attainable goal"; "art is not something that is come-at-able by dint of study")

INDIRECT (VIA possible) -> impossible -- (not capable of occurring or being accomplished or dealt with; "an impossible dream"; "an impossible situation")

Similarity of adj attainable

1 sense of attainable

Sense 1
attainable, come-at-able -- (capable of being attained or accomplished; "choose an attainable goal"; "art is not something that is come-at-able by dint of study")
       => possible (vs. impossible) -- (capable of happening or existing; "a breakthrough may be possible next year"; "anything is possible"; "warned of possible consequences")