Definition of "line of defence" [line of defence]

• Defensive structure consisting of a barrier that can be employed for defense against attack (noun)
• Any organization whose responsibility it is to defend against something (noun)

WordNet. Princeton University. 2010.

• "To this stream, the natural line of defence of the city on the north and east, numerous roads diverged from the capital, including the York River Railroad, of which the Federal commander made such excellent use; and General McClellan had thrown his left wing across the stream, advancing to a point on the railroad four or five miles from the city."
• "I sunk, burnt, captured, or drove into the harbour, the whole line of defence to the southward of the Crown Islands."
• "Supposing them safe through the Belts, the heavy ships could not come over the GROUNDS to attack Copenhagen; and light vessels would have no effect on such a line of defence as had been prepared against them."