Path at both ends blocked by small rocks (5)
I believe the answer is:
sways
'rocks' is the definition.
(I've seen this in another clue)
'path at both ends blocked by small' is the wordplay.
'path' becomes 'alley' (alley is a kind of path).
'at both ends' means to remove the middle letters (only the letters at the ends of the word).
'blocked' indicates putting letters inside (to block can mean to box in or contain).
'by small' becomes 'sws' (I can't explain this - if you can you should believe this answer much more).
'alley' with its middle removed is 'ay'.
'ay' put within 'sws' is 'SWAYS'.
Can you help me to learn more?
(Another definition for sways that I've seen is " Swings".)