1. blind alley, cul de sac, dead-end street, impasse, thoroughfare
usage: a street with only one way in or out
2. blind alley, course, course of action
usage: (figurative) a course of action that is unproductive and offers no hope of improvement; "all the clues led the police into blind alleys"; "so far every road that we've been down has turned out to be a blind alley"