Synonyms: half-baked, softheaded, screwball, crazy
Definition: foolish; totally unsound
Usage: a crazy scheme; half-baked ideas; a screwball proposal without a prayer of working
Similar words: impractical
Definition: not practical; not workable or not given to practical matters
Usage: refloating the ship proved impractical because of the expense; he is intelligent but too impractical for commercial work; an impractical solution