un ‧ work ‧ a ‧ ble /ʌnˈwɜːkəb ə l $ -ɜːr-/ BrE AmE adjective
[ Word Family: noun : ↑ work , ↑ workaholic , ↑ worker , ↑ working , WORKINGS ; adjective : ↑ workable ≠ ↑ unworkable , ↑ overworked , ↑ working ; verb : ↑ work , ↑ rework ]
an unworkable plan, system, law etc is not likely to be successful