1. A weight on the end of a line, used to determine water depth.
2. A weight on the end of a line, used especially by masons and carpenters to establish a true vertical.
1. In a vertical or perpendicular line.
2. Informal Directly; squarely: fell plumb in the middle of the puddle.
3. also plum Informal Utterly; completely: plumb worn out. right
1. Exactly vertical. See Synonyms at vertical.
2. also plum Informal Utter; absolute; sheer: a plumb fool.
v. plumbed, plumb·ing, plumbs
1. To determine the depth of with a plumb; sound.
2. To test the verticality or alignment of with a plumb.
3. To straighten or make perpendicular: plumb up the wall.
4. To examine closely or deeply; probe: "Shallow ideas are plumbed and discarded" (Gilbert Highet).
5. To seal with lead.
6. To outfit with or connect to a plumbing system: plumbed the utility closet so a washing machine could be installed.
To work as a plumber.
off/out of plumb
[Middle English, lead, a plumb, from Old French plomb, from Latin plumbum, lead.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus