Money keeps fifty engaged in conflict (5)
I believe the answer is:
clash
'engaged in conflict' is the definition.
'clash' can be an answer for 'conflict' (clash is a kind of conflict). I am not certain of the 'engaged in' bit.
'money keeps fifty' is the wordplay.
'money' becomes 'cash' (cash is a type of money).
'keeps' indicates putting letters inside (inserted letters are kept inside).
'fifty' becomes 'l' (Roman numeral).
'cash' placed around 'l' is 'CLASH'.
Can you help me to learn more?
(Other definitions for clash that I've seen before include "Loud noise - conflict" , "Come into violent conflict" , "Conflict, between colours say" , "Forceful disagreement" , "Fail to fit" .)