Synonym of guardrail

A large wide board similar to a surfboard used for surf lifesaving. It is propelled by the rescuer (usually a lifeguard) paddling using their arms, either lying face down or sitting up on their knees, and usually has straps along the sides to hold onto.

Synonym of daughterboard

A sport resembling snowboarding, but performed on volcanic ash on the slopes of a volcano.

(climbing) A form of bouldering performed on a (usually wooden) climbing wall compact enough to fit at home but covered with many climbing holds, often done as practice for standard bouldering.

Wearing board shorts.

(computing, historical) A type of computer system, now largely obsolete, used to exchange messages and data over a telecommunications network.

(idiomatic) All over the map.

(electronics) A flat board that holds chips and other electronic components in layers that interconnect via copper pathways, often called traces.

(idiomatic) Back to the beginning following an unsuccessful attempt.