### Clue: Potter's work in poem has pun that's awful (3-9)
### Answer: ONE-UPMANSHIP 
 ### Explanation: Definition: Potter's work
  **Anagram of**(that's awful) IN POEM HAS PUN
Defn:  Book by Stephen Potter (1900-1969), a spoofy "self-help" book on how to be one-up on the other guy.  Other of his books include "Gamesmanship", "Lifemanship","Supermanship" and "The Complete Golf Gamesmanship".