### Clue: One long imprisoned in doomed fort's war cry of old (9)
### Answer: ALALAGMOS 
 ### Explanation: Definition: war cry of old
A LAG in ALAMO'S – the preamble says that this "appears in earlier editions"; as I don't have the latest edition I can't verify that it doesn't appear in that, but it is in the 11th Edition (2008)