Possible Clues:

• Like a contained enemy
• One way to be held
• Good spot to keep an enemy
• Cornered in a seaside borough, soldiers needing to escape
• Like a cornered wild animal
• Unable to flee for a time on horse
• Up a tree
• Like an animal with its back against the wall (2 words)
• Rhyme and synonym of 'away'
• Kept in check