Peers into vessel, bonnet having been pulled back (8)
I believe the answer is:
noblesse
'peers' is the definition.
(peers are members of the nobility)
'into vessel bonnet having been pulled back' is the wordplay.
'into' indicates the answer is hidden within the clue.
'having been pulled back' says the letters should be written in reverse.
'esselbon' is hidden within 'vessel bonnet'.
'esselbon' in reverse letter order is 'NOBLESSE'.
(Other definitions for noblesse that I've seen before include "- - oblige (Fr.)" , "Privilege has its responsibilities (in French) - . . . . . . . . oblige" , "Foreign toffs" , "peers" , "aristocrats" .)