This idiom indicates an unrealistic or impractical plan or theory.

这个成语现在比喻不现实或者不可行的计划或者理论等。

youdao

The plan was so shallow and impractical that no serious attempt was ever made to realize it.

不过这项计划是如此肤浅和不切实际，以至于没有人会认真尝试来实现它。

youdao

The plan is feasible in reason but impractical.

这个计划道理上行得通，但不现实。

youdao

Administration officials said they didn't hew closely to the existing emergency plan, because they found some of it impractical, including complex rules outlining how local governments should ask for help.

WSJ: Poor Training Fueled Gas Shortage After Sandy