Section of trestle's stood on edge (8)
I believe the answer is:
restless
'on edge' is the definition.
(thesaurus)
'section of trestle's stood' is the wordplay.
'section of' says the answer is hidden in the clue.
'RESTLESS' is hidden in the letters of 'trestles stood'.
(Other definitions for restless that I've seen before include "Unable to relax or be still" , "Always on the move" , "Unsettled, fidgety" , "Ill at ease" , "Never still" .)