From The Collaborative International Dictionary of English v.0.48 [gcide]:
Impractical \Im*prac"ti*cal\, a.
Not practical.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
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"; "an impractical solution" [ant:
practical]
2: not practical or realizable; speculative; "airy theories
about socioeconomic improvement"; "visionary schemes for
getting rich" [syn: airy, impractical, visionary,
Laputan, windy]