### Clue: Sect takes up clergyman involved in a runaway affair (7)
### Answer: CULVERT 
 ### Explanation: Definition: a runaway affair
  CULT(religious or pseudo-religious *sect*) around(*takes*) reversal(*up*, in a down clue) of REV(the $$Rev$$erend so and so,*clergyman*)
Defn:  Basically a drain to take runoff,*runaway* water