What bowler aims at from square leg? (7)
I believe the answer is:
Here is my best explanation:
'what bowler aims at' is the definition.
'square leg?' is the subsidiary indication.
'square' becomes 'nine' (I've seen this before).
'leg?' becomes 'pin' (pin is a kind of leg).
'from' is the link.
(Other definitions for ninepin that I've seen before include "over one goes", "Target", "Type of bowling", "game", "What bowler tries to hit", "Skittle" and "target to knock over".)