### Clue: Ruin surrounds husband immersed in drink, the rodent (9)
### Answer: GROUNDHOG 
 ### Explanation: Definition: rodent
 [UNDO(to ruin/to cause the downfall of) **containing**(surrounds) H(abbrev. for "husband")] **contained in**(in) GROG(an alcoholic drink of spirit, originally rum, mixed with water).