A relief valve set to open at a pressure below that at which a container (such as a boiler) would burst. / (figuratively) Any mechanism offering relief from pressure or tension, e.g. emotionally.

A surname.

On the left side. / Towards the left side. / Towards the political left.

(botany) The tissues formed of elongated cells, especially those with pointed or oblique extremities, such as the principal cells of ordinary wood.