### Clue: It might herald a long dry period? (11)
### Answer: PROHIBITION 
 ### Explanation: Definition: It might herald a long dry period
 Cryptic defn: Reference to the period 1920 – 1933 in the US when the manufacture, transportation and sale of alcoholic drinks were prohibited;a long period to be alcohol-free;dry. Needless to say, quite a few broke the law.