1. Any mass used to balance a load. Includes
stage weights as well as
sandbags.
2.
Stage rigging. A "brick" made of steel, cast
iron, or lead placed in an
arbor and used to balance the load on a
batten. Also known as a
stage weight or
pig iron.
Theatre & Stage Equipment Products - Manual Rigging - Counterweights
For discussion, see the thread
Stage Weights.