Bridge

[1] A metal support which is installed in the valve slot of a wheel rim and prevents the flap and tube from bulging through the slot under high pressure and high heat conditions. Also called lemna.
[2] Circuit often used for measurement of the impedance of passive components, for both ac and dc. Four arms of the bridge are arranged in a diamond-shaped configuration, three comprising accurately known impedances and the fourth, the unknown. A voltage supply is connected to two opposite corners of the diamond and a detector between the other two. By adjusting the known component values, the bridge is balanced when the detector shows a null signal and equations are then available for the unknown in terms of the other three arms of the bridge.
[3] A structure spanning a river, road, etc. giving communication across it.
See also arch bridge, bailey bridge, balance-bridge, bowstring bridge, flying bridge, house bridge, navigating bridge, port bridge