### Clue: I help one drunk to swallow old grape nut (9)
### Answer: OENOPHILE 
 ### Explanation: Definition: grape nut
  **Anagram of**(drunk) [I HELP ONE] **containing**(to swallow) O(abbrev. for "old").
Answer:  The suffix -phile indicating a nut,fan,connoisseur, or just someone who enjoys "the grape",wine, represented by the prefix oeno-.