impracticable

形容词 impracticable:

1. not capable of being carried out or put into practice
   同义词：infeasible, unfeasible, unworkable

1. Originally Edison used platinum alloys for the filament, in the belief that carbon was impracticable.
   爱迪生不相信碳可作灯丝用，所以一开始就用铂合金作灯丝。
2. It's evident that the plan is impracticable.
   很明显这计划是不能实现的。
3. The plan is impracticable.
   这个计划是不可行的。
4. It was impracticable to think that we could build the house in one week.
   以为我们用一周的时间就能把房子盖好，这种想法是不切实际的。

im.prac.ti.ca.ble

adj.（形容词）
Impossible to do or carry out:
不能实行的，行不通的：
例句：
Refloating the sunken ship intact proved impracticable because of its fragility.
由于沉船的易碎性使整艘沉船的重新上浮被证明是行不通的

Unfit for passage:
不适于通行的：
例句：
roads impracticable in winter.
在冬天不能通行的路

Archaic Unmanageable; intractable.
【古语】 难处理的；难对付的

【引伸】
imprac.ticabil.ity 或
imprac.ticableness
n.（名词）
imprac.ticably
adv.（副词）
Impracticable applies to a course of action that is impossible to carry out or put into practice;impractical, though it can be used in this way, also can be weaker in sense,suggesting that the course of action would yield an insufficient return or would have little practical value.A plan for a new baseball stadium might be rejected asimpracticable if the site was too marshy to permit safe construction; but if the objection was merely that the site was too remote for patrons to attend games easily,the plan would better be described asimpractical. See Usage Note at practicable
Impracticable 用于不可能实行或行不通的动作过程；impractical 虽然也能这样用， 但也有较弱意思的用法，指动作过程能产生不足的回报或者几乎没有实际的价值。如果建筑地点过于湿软而不能保证稳固的建筑，那么修建棒球体育场的计划就可能因其impracticable （不可行）而遭到反对； 但是如果反对的理由仅仅是场址太偏远而使得爱好者们不能轻易到场观看比赛的话，这个计划还是应该被看成是impractical（不切实际的） 参见 practicable