n. A little mass or weight of lead, or the like, attached to a line, and used by builders, etc., to indicate a vertical direction; a plummet; a plumb bob. See Plumb line, below. Plumb bob. See Bob.
- Plumb joint, in sheet-metal work, a lap joint, fastened by solder.
- Plumb level. See under Level.
- Plumb line. (a) The cord by which a plumb bob is suspended; a plummet. (b) A line directed to the center of gravity of the earth.
- Plumb rule, a narrow board with a plumb line, used by builders and carpenters.
- adj. Perpendicular; vertical; conforming the direction of a line attached to a plumb; as, the wall is plumb.
- adv. In a plumb direction; perpendicularly.
- vb. To adjust by a plumb line; to cause to be perpendicular; as, to plumb a building or a wall. 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. To seal with lead; as, to ...