Be active in Samaritan organisation preserving international philanthropy (15)
I believe the answer is:
humanitarianism
'philanthropy' is the definition.
(thesaurus)
'be active in samaritan organisation preserving international' is the wordplay.
I cannot really see how this works, but
'be' could be 'hum' (humming is a kind of being) and 'hum' is found within the answer.
'active' could be 'a' (grammatical abbreviation) and 'a' is present in the answer.
'international' could be 'i' (abbreviation eg in IMF) and 'i' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for humanitarianism that I've seen is " concern for welfare".)