Good person, monarch in support group for condition (6)
I believe the answer is:
asthma
'condition' is the definition.
(asthma is a kind of condition)
'good person monarch in support group' is the wordplay.
'good person' becomes 'st' (saint).
'monarch' becomes 'hm' (abbreviation for His or Her Majesty).
'in' means one lot of letters goes inside another.
'support group' becomes 'aa' (I can't justify this - if you can you should give a lot more credence to this answer).
'st'+'hm'='sthm'
'sthm' placed inside 'aa' is 'ASTHMA'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for asthma that I've seen before include "Respiratory disease" , "Breathing illness" , "Respiratory disorder with wheezing" , "Cause of breathing difficulty" , "inspiring trouble" .)