plural of sound barrier

A safety feature of auto racing venues, consisting of stacked tires secured together, that provides a cushion in the event of an impact.

A massive system of coral reefs, found in the Coral Sea off the coast of Australia.

Lacking barriers / (chemistry) Not requiring activation energy

plural of Coulomb barrier

(roofing) noncombustible board stock material of low thermal conductivity placed between two elements of a roof assembly.

plural of crash barrier

A barrier on the side of a road, to keep vehicles on the road.

The blood-brain barrier.

(anatomy) A structure in the central nervous system (CNS) that keeps various substances found in the bloodstream out of the brain while allowing in the substances essential to metabolic function, e.g. oxygen.