1.The guarding or protecting of the left lane on an interstate using an unreasonably small following distance.

2. Preventing other motorists from entering the fast lane when the situation arises.
There were at least 3 cars in front of me with their left blinker on during stop and go traffic on the highway. However, they could not shift over while I had my left lane defense up.
by RAD_revolution July 24, 2010
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