A plan, rule, system, or idea that cannot actually be made to work in real life. "The proposal was rejected as unworkable." "Their timetable turned out to be completely unworkable." The important thing is what kind of failure this is. `Unworkable` does not mean wrong, and it does not mean stupid. The idea may be beautiful on paper — fair, clever, popular. It simply falls apart when real people, real money, and real time touch it. There is not enough staff, the steps contradict each other, nobody could follow the rules. So the word carries a faint tone of "nice thought, but come back to earth." It attaches to plans, not to objects and not to people. You would not say an unworkable chair or an unworkable student. Plan, scheme, system, solution, policy, arrangement, law, compromise — those are its friends. Register: neutral-to-formal, very common in business, politics, and news. It is one of those `un- + -able` words that a student can use safely and sound quite grown-up. Watch for the strengtheners it invites: `simply unworkable`, `completely unworkable`, `politically unworkable`, `unworkable in practice`.

行不通的、窒礙難行的（計畫、制度、辦法等實際上做不起來）