不通

bùtōng
  1. to be obstructed
  2. to be blocked up
  3. to be impassable
  4. to make no sense
  5. to be illogical

CEDICT

Entry Composition

1 不 bù
  1. no; not so
  2. (bound form) not; un-
2 通 tōng
  1. to go through
  2. to know well
  3. (suffix) expert
  4. to connect
  5. to communicate
  6. open
  7. to clear
  8. classifier for letters, telegrams, phone calls etc