Source : Webster's Revised Unabridged Dictionary (1913)

Impractical \Im*prac"ti*cal\, a.
   Not practical.

Source : WordNet®

impractical
     adj 1: not practical; not workable or not given to practical
            matters; "refloating the ship proved impractical
            because of the expense"; "he is intelligent but too
            impractical for commercial work" [ant: {practical}]
     2: not practical or realizable; speculative; "airy theories
        about socioeconomic improvement"; "visionary schemes for
        getting rich" [syn: {airy}, {visionary}, {Laputan}]