1.To adjust by a plumb line; to cause to be perpendicular; as, to plumb a building or a wall.
2.To sound with a plumb or plummet, as the depth of water; hence, to examine by test; to ascertain the depth, quality, dimension, etc.; to sound; to fathom; to test. "He did not attempt to plumb his intellect."
3.To seal with lead; as, to plumb a drainpipe.
4.To supply, as a building, with a system of plumbing.
