WordNet
n. any organization whose responsibility it is to defend against something; "police are the major line of defense against crime" [syn: line of defence]
defensive structure consisting of a barrier that can be employed for defense against attack [syn: line of defence]
Usage examples of "line of defense".
Suddenly the idea of a single line of defense was not so ridiculous.
The indicators were that the horde of Posleen infantry would be the first to reach the hastily drawn line of defense.
Most important of all, there was to be no direct route to the rear from the primary line of defense.
After blowing up the bridge at Nimy they fell back, company by company, to a second line of defense that had been prepared two or three miles to the rear.
On the ridge, the Elven line of defense had been forced backward almost to the mouth of the canyon.
A difficult strategic problem-we're too far from the best line of defense, Landsdrop.