Viscounts' superiors (5)
I believe the answer is:
earls
'viscounts' superiors' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for earls that I've seen before include "counts" , "Lear's out for the flight of the nobility" , "Laser the British peers" , "Noblemen (with a Court?)" , "Nobles" .)