### Clue: General charges with sergeant perhaps to stop army heading off (6)
### Answer: ONCOST 
 ### Explanation: Definition: General charges
 NCO(abbrev. for "non-commissioned officer", an example of which/perhaps is a sergeant) **contained in**(to stop) "host"(archaic term for an army) **minus its 1st letter**(heading off).
Defn: …/an overhead expense.