plumb

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

• noun A weight on the end of a line, used to determine water depth.
• noun A weight on the end of a line, used especially by masons and carpenters to establish a true vertical.
• adverb In a vertical or perpendicular line.
• adverb Informal Directly; squarely.
• adverb Informal Utterly; completely.
• adjective Exactly vertical. synonym: vertical.
• adjective Informal Utter; absolute; sheer.
• intransitive verb To determine the depth of with a plumb; sound.
• intransitive verb To test the verticality or alignment of with a plumb.
• intransitive verb To straighten or make perpendicular.
• intransitive verb To examine closely or deeply; probe.
• intransitive verb To seal with lead.
• intransitive verb To work as a plumber.
• idiom (off/out of) Not vertical.

from The Century Dictionary.

• To adjust by a plumb-line; set in a vertical position: as, to plumb a wall or a building.
• To sound with or as with a plummet, as the depth of water.
• To ascertain the measure, dimensions, capacity, or the like, of; test-
• To supply, as a building, with lead pipes for water, sewage, etc.
• In a vertical direction; in a line perpendicular to the plane of the horizon; straight down.
• Exactly; to a nicety; completely: as, he hit the target plumb in the bull's-eye.
• Downright; entirely; altogether.
• noun A mass of lead attached to a line, used to test the perpendicularity of walls, etc.; a plummet.
• noun The position of a plumb or plummet when freely suspended; the vertical or perpendicular.
• In plumbing, to seal an opening by closing it with solder or other soft metal.
• To coincide in direction with the plumb-line; be vertically above or below.
• True according to a plumb-line; vertical.
• Of persons, upright in character or conduct; thoroughgoing.
• An obsolete spelling of plum.

from the GNU version of the Collaborative International Dictionary of English.

• adverb In a plumb direction; perpendicularly.
• noun 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.
• noun See Bob, 4.
• noun in sheet-metal work, a lap joint, fastened by solder.
• noun See under Level.
• noun A line directed to the center of gravity of the earth.
• noun a narrow board with a plumb line, used by builders and carpenters.
• transitive verb To adjust by a plumb line; to cause to be perpendicular.
• transitive verb 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.
• transitive verb To seal with lead.
• transitive verb To supply, as a building, with a system of plumbing.
• adjective Perpendicular; vertical; conforming the direction of a line attached to a plumb.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective truly vertical
• adjective cricket Describing an LBW where the batsman is hit on the pads directly in front of his wicket and should be given out.
• adverb In a vertical direction.
• adverb informal Squarely, directly; completely.
• noun A little mass of lead, or the like, attached to a line, and used by builders, etc., to indicate a vertical direction.
• noun nautical A weight on the end of a long line, used by sailors to determine the depth of water.
• verb To determine the depth, generally of a liquid; to sound.
• verb To attach to a water supply and drain.
• verb To think about or explore in depth, to get to the bottom of, especially to plumb the depths of.
• verb To use a plumb bob as a measuring or aligning tool.