The 3rd bridge is an extended playing technique used on mainly electric guitars such as the Fender Jazzmaster that has the strings continue through to the tremolo piece. It is called the 3rd Bridge because some players utilized the unique sound that one can get out of playing in that area. Bands like Sonic Youth and Placebo are known for using this technique. Other more common use of the term contains a prepared guitar with a rod, for instance a screwdriver or pencil, placed between the fretboard and strings. In that case the strings are played at the side of the fretboard, causing a resonating overtone at the string part above the pickup.
