Instrument bent with room to manoeuvre (8)
I believe the answer is:
trombone
'instrument' is the definition.
(trombone is a kind of instrument)
'bent with room to manoeuvre' is the wordplay.
'with' is a charade indicator (letters next to each other).
'to manoeuvre' is an anagram indicator.
'bent'+'room'='bentroom'
'bentroom' anagrammed gives 'TROMBONE'.
(Other definitions for trombone that I've seen before include "Musical instrument with long slide" , "Brass musical instrument with slide" , "Brass instrument with sliding tubes" , "Brass band instrument" , "source of notes" .)