stuffing box

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An enclosure containing packing to prevent leakage around a moving machine part.

from The Century Dictionary.

• noun In machinery, a contrivance for securing a steam-, air-, or watertight joint when it is required to pass a movable rod out of a vessel or into it.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a small chamber in which packing is compressed around a reciprocating shaft or piston to form a seal