Dormant in insect net, a locust turned up (6)
I believe the answer is:
latent
'dormant' is the definition.
(I've seen this before)
'in insect net a locust turned up' is the wordplay.
'in' says the answer is hidden in the clue.
'turned up' shows that the letters should be reversed in order.
'tnetal' is hidden within 'insect net a locust'.
'tnetal' written backwards gives 'LATENT'.
(Other definitions for latent that I've seen before include "Potential but not active" , "Talent (anag)" , "Unrealised, potential" , "waiting to be discovered" , "Not yet visible or developed" .)