Some nobles
I think it could be either:
'some nobles' is the definition.
(earl is a kind of noble)
This is all the clue.
(Other definitions for earls that I've seen before include "members of the House of Lords" , "Laser the British peers" , "Noblemen (with a Court?)" , "They're below marquess and above viscount" , "Nobles" .)
'some nobles' is the definition.
(I know this)
This is the entire clue.
(Other definitions for lords that I've seen before include "Titled noblemen" , "Cricket venue" , "London cricket ground" , "Peers - setting for many an 6 test" , "British upper house" .)