Safety feature at a trapeze school (3)
I believe the answer is:
net
'safety feature at a trapeze school' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for net that I've seen before include "Trap; open-weave fabric" , "Clear profit or gain" , "Fine open-weave fabric" , "device to divide the court" , "Meshed trap" .)