### Clue: Force top Frenchman to return in middle of site (6)
### Answer: IMPACT 
 ### Explanation: Definition: Force
 **Reversal of**(… to return) [CAP(a top/a cover or lid) + M(abbrev. for "Monsieur", a form of address for a Frenchman)] **contained in**(in) **the middle2 letters of**(middle of) "site".