| Answer | Crossword Clue |
|---|---|
| IMPASSABLE | Insurmountable. |
| BIGLEADS | They can be insurmountable |
| STYMY | Minor but insurmountable obstacle: Var. |
| insurmountably | INSURMOUNTABLE, incapable of being surmounted |
| THEATRE | A series of "insurmountable obstacles on the road to imminent disaster," per Tom Stoppard |
