At an automatic half-barrier level crossing, a lifting barrier that does not block the whole road when in the horizontal position, placed on the left side in the UK according to driving on the left, and mostly used on narrower or quieter roads instead of two lifting barriers either side of the railway crossing.

plural of half-barrier

Synonym of crash barrier

plural of traffic barrier

(physics) A metal-semiconductor junction which functions as a rectifier.

A conceptual barrier to effective communication, occurring when people who speak different languages attempt to communicate with each other.

(physics) the barrier between two atomic nuclei, due to Coulomb repulsion, that has to be overcome for nuclear fusion to proceed

(uncountable) Sonic barrier, the sudden increase in drag (resistance) and other effects experienced by moving objects when their speed approaches that of sound or becomes supersonic (which used to be considered a barrier to higher speeds).

A means of contraception involving an impenetrable barrier, such as a diaphragm or condom, between sexual partners.

Synonym of tollbar