Rock where hard seeds turned up (4)
I believe the answer is:
stun
'rock' is the definition.
(I've seen this in another clue)
'seeds turned up' is the wordplay.
'seeds' becomes 'nuts' (nut is a kind of seed).
'turned up' shows that the letters should be reversed in order.
'nuts' backwards is 'STUN'.
'where hard' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for stun that I've seen before include "Anaesthetise" , "Shock, flabbergast" , "floor" , "Render semi-conscious with blow" , "Daze or bewilder" .)