Less generous, being more lowly bred (6)
I believe the answer is:
meaner
'less generous' is the definition.
(I've seen this before)
'lowly bred' is the wordplay.
'lowly' becomes 'mean'.
'bred' becomes 'er' (I can't justify this - if you can you should believe this answer much more).
'mean'+'er'='MEANER'
'being more' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for meaner that I've seen before include "Rename as being more stingy" , "More miserly" , "Less generous" , "More stingy or parsimonious" , "Rename as being stingier" .)