### Clue: Extremely enthusiastically supports alcoholic in his normal manner of behaving (9)
### Answer: DRUNKENLY 
 ### Explanation: Definition: his normal manner of behaving
 **The 1st 2 and the last 2 letters of**(Extremely) "enthusiastically " **placed below**(supports, in a down clue) DRUNK(an alcoholic).
Defn: …, an alcoholic's, that is.