Noblemen losing heart with working individual (6)
I believe the answer is:
person
'individual' is the definition.
('person' can be a synonym of 'individual')
'noblemen losing heart with working' is the wordplay.
'noblemen' becomes 'peers' (peer is a kind of nobleman).
'losing heart' means to remove the middle letters.
'with' says to put letters next to each other.
'working' becomes 'on'.
'peers' with its middle taken out is 'pers'.
'pers'+'on'='PERSON'
(Other definitions for person that I've seen before include "Type" , "anyone else" , "Individual human being" , "Bod" , "character" .)