siege
noun
[ siːdʒ ]
• a military operation in which enemy forces surround a town or building, cutting off essential supplies, with the aim of compelling those inside to surrender.
• "Verdun had withstood a siege of ten weeks"
• a group of herons.
• "there is a siege of herons at the river"
Origin:
Middle English: from Old French sege, from asegier ‘besiege’.
under siege
• (of a place) undergoing a siege.
• "the fort had been under siege by guerrillas since June"