Get stuck in cave in undulating hill (6,4)
I believe the answer is:
buckle down
'get stuck' is the definition.
Although both the answer and definition are verbs in their base form, I cannot understand how they can define each other.
'cave in undulating hill' is the wordplay.
I cannot quite see how this works, but
'cave' could be 'buckle' (both can mean to give up or collapse) and 'buckle' is located in the answer.
'hill' could be 'down' (I've seen this in other clues) and 'down' is found in the answer.
No letters remain.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for buckle down that I've seen before include "work hard" , "focus!" , "Tackle a task with determination" .)