The definition of a barrier is anything, either natural or manmade, that keeps something from passing through.(noun)
An example of a barrier is a fence.
See barrier in Webster's New World College Dictionary
Origin: ME barrere < OFr barriere < barre, bar
See barrier in American Heritage Dictionary 4
Origin: Middle English barrer
Origin: , from Old French barriere
Origin: , from Vulgar Latin *barrāria
Origin: , from *barra, bar.
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