Fish beneath rocks to glide on frozen pond (3,5)
I believe the answer is:
ice skate
'glide on frozen pond' is the definition.
'fish beneath rocks' is the wordplay.
'fish' becomes 'skate' (skate is a kind of fish**).
'beneath' is a charade indicator (letters next to each other) (in a down clue).
'rocks' becomes 'ice' (I've seen this before).
'skate' after 'ice' is 'ICE-SKATE'.
'to' is the link.
(Other definitions for ice skate that I've seen before include "Shoe with runner" , "it makes progress in an entertainment centre" , "Use blade to go" , "Attachment to a winter sport's boot" , "Curry required more than one" .)