Moment right to return doctor's instruments (9)
I believe the answer is:
trombones
'instruments' is the definition.
(trombone is a kind of instrument)
'moment right to return doctor's' is the wordplay.
'moment' becomes 'mo' (as in 'just a mo').
'right' becomes 'rt' (abbreviation as in Rt Hon- the Right Honourable).
'to return' is a reversal indicator.
'doctor' becomes 'bones' (bones can informally mean a doctor).
'mo'+'rt'='mort'
'mort' backwards is 'trom'.
'trom'+'bones'='TROMBONES'
(Other definitions for trombones that I've seen before include "Their slides have seven positions" , "Seventy six were noted!" , "Brass instruments" .)