### Clue: Socialist has fix on how fight can be ended (5)
### Answer: PINKO 
 ### Explanation: Definition: Socialist
 PIN(to fix something on to something else) **placed above**(on, in down clue) KO(abbrev. for "knock out"/how a boxing match/fight can be ended, specifically with one fighter down for a count of ten).
Defn: … with left-wing views.