A bridged amplifier is a configuration for creating a larger voltage than possible with one amplifier by inverting a second amplifier and connecting the load to both outputs. This is similar to a push-pull amplifier.

In other words, if a single amplifier is able to produce ±10 V max relative to ground, a second amplifier can output the same signal, but inverted. If the load is connected across the positive outputs of both amplifiers, it sees +10 V - -10 V = 20 V total, which is double what each individual amplifier can put out. This is often an option on stereo power amplifiers for audio to increase the power available for a monaural signal.