- a street or passage closed at one end.；a route or course leading nowhere
noun: cul-de-sac, plural noun: culs-de-sac
- 1. a street or passage closed at one end.
- ▪ a route or course leading nowhere the first six months of the investigation were a frustrating cul-de-sac for police, tips and leads going nowhere
- ▪ a vessel, tube, or sac, e.g., the cecum, open at only one end.
- a street or passage closed at one end.