Sends round a small sum in allowances (8)
I believe the answer is:
stipends
'allowances' is the definition.
(type of financial payment)
'sends round a small sum' is the wordplay.
'round' means one lot of letters goes inside another.
'a small sum' becomes 'tip' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'sends' enclosing 'tip' is 'STIPENDS'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for stipends that I've seen before include "Allowances (clergy)" , "Regular payments" , "fixed wages" , "Spends it on clergymen's salaries" , "Salaries of clergymen" .)