Related Clues:

• Hear stammerer's marked as bore
• Military operation to seal off (town)
• Military encirclement
• Galahad's dangerous seat
• Diocese gets regular income from one good investment
• Military operation ringing a town
• Military operation cutting off access
• Kept going as new duties are ordered
• A good investment by O'Brien
• Steady date with sinus trouble
• Isolating attack
• Blockade of a town or fortress
• American implicated by dirty Fed
• Steadily maintained
• Challenge for defenders