debar (v.)

early 15c., "to shut out, exclude," from French débarrer, from Old French desbarer (12c., which, however, meant only "to unbar, unbolt," the meaning turned around in French as the de- was felt in a different sense), from des- (see dis-) + barrer "to bar" (see bar (n.1)). Related: Debarment; debarred.