Plumb

1. adv. In a plumb direction; perpendicularly.
2. 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.
3. a. Perpendicular; vertical; conforming the direction of a line attached to a plumb; as, the wall is plumb.
4. v. t. To seal with lead; as, to plumb a drainpipe.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.