A structure erected to span natural or artificial obstacles, such as rivers, highways, or railroads, and supporting a footpath or roadway for pedestrian, highway, or railroad traffic.

A device that joins two networks of the same type.

1. An electrical instrument having four or more branches, by means of which one or more of the electrical constants of an unknown component may be measured.

2. An electrical shunt path.

A line whose removal disconnects a component of a graph. Also known as isthmus.

A piece of timber held above the cap of a set by blocks and used to facilitate the driving of spiling in soft or running ground.

An elevated structure extending across or over the weather deck of a vessel, containing stations for control and visual communications.

A connection between two different parts of a molecule consisting of a valence bond, an atom, or an unbranched chain of atoms.

1. An obstruction in a borehole resulting from the wall caving or the presence of a large boulder.

2. A device installed in a borehole either permanently or temporarily to retain cement or other material.