1. A small, round, heavily fortified tower built for coastal defense, typically with a gun platform on top.
Usage: historical; often used in the plural as 'martello towers'

Examples

• The martello towers were built along the English coast to defend against French invasion.
• Visitors can tour the restored martello tower on the island.
• The British constructed dozens of martellos during the Napoleonic Wars.
• The martello's circular design made it difficult for enemy cannons to damage.