WordWeb Online

1. A situation in which no progress can be made or no advancement is possible
   "reached an impasse on the negotiations";
   - deadlock, dead end, stalemate, standstill
    
2. A street with only one way in or out
   - blind alley, cul de sac, dead-end street

Derived forms: impasses

Type of: situation, thoroughfare

Encyclopedia: Impasse