11 across
Fixed
time
around
rugged
ridges
(6)
Fixed time around rugged ridges (6)
hints
0
checks
0
hints
The definition is at the end of the clue.
How the clue works
The definition is rugged ridges, which aretes are (sharp mountain ridges). SET (fixed) plus ERA (time) gives SETERA, which is reversed by "around" to produce ARETES.