Grasp retreats on fateful Gallipoli ridge (3)
I believe the answer is:
nek
'fateful gallipoli ridge' is the definition.
The definition suggests a singular noun which matches the answer.
'grasp retreats' is the wordplay.
'grasp' becomes 'ken' (I've seen this in another clue).
'retreats' says the letters should be written backwards (I've seen 'retreating' mean this).
'ken' reversed gives 'NEK'.
'on' acts as a link.
Can you help me to learn more?
(Another definition for nek that I've seen is " mountain pass".)