ground lift

1. Electrical. A device allowing modern three-prong cords to be inserted in older, two-wire receptacles. For proper operation, the ground lug or wire MUST be attached to the faceplate screw. These should NOT be used to solve audio hum or buzz issues, and their use most likely violates all current electrical codes.

http://www.electronicplus.com/images/products/419GY.jpg


2a. Audio. A male XLR3 to female XLR3 with no connection between the #1 contacts. More correctly should be termed a "Pin 1 Lift."

Whirlwind / Specialty Interface Devices

See this thread for discussion.
2b. Audio. A rocker or toggle switch, most often found on a direct box, that accomplishes the above.