plumb line


Definition of plumb line

1 : a line (as of cord) that has at one end a weight (such as a plumb bob) and is used especially to determine verticality
2 : a line directed to the center of gravity of the earth : a vertical line

Examples of plumb line in a Sentence

Recent Examples on the Web Four weighted plumb lines hung from the ends of the arms. Kiona N. Smith, Ars Technica, "Floor pavements in Pompeii illustrate surveying technology," 7 Dec. 2019 Then gently unroll the paper strips onto the wall, working your way from top to bottom, and keeping the edge of the paper aligned with the plumb line. Daniel Bortz, sacbee, "Four home-improvement jobs you can knock out," 15 June 2018 My father’s simple existence has been like a horizontal plumb line for me, one to gauge myself against. R. Daniel Foster, WSJ, "A Father’s Lesson: Keep the Spirit Level," 14 June 2018 Thankfully the technology used today has advanced beyond dangling plumb lines over the side of the ship. Kyle Frischkorn, Smithsonian, "Why The First Complete Map of the Ocean Floor Is Stirring Controversial Waters," 13 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'plumb line.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of plumb line

15th century, in the meaning defined at sense 1

Keep scrolling for more

Learn More about plumb line

Time Traveler for plumb line

Time Traveler

The first known use of plumb line was in the 15th century

See more words from the same century

Statistics for plumb line

Cite this Entry

“Plumb line.” Dictionary, Merriam-Webster, Accessed 14 Jul. 2020.

Keep scrolling for more

More Definitions for plumb line

plumb line


English Language Learners Definition of plumb line

: a tool that consists of a small, heavy object attached to a string or rope and that is used especially to see if something (such as a wall) is perfectly vertical

Keep scrolling for more

More from Merriam-Webster on plumb line

Rhyming Dictionary: Words that rhyme with plumb line

Nglish: Translation of plumb line for Spanish Speakers Encyclopedia article about plumb line

Comments on plumb line

What made you want to look up plumb line? Please tell us where you read or heard it (including the quote, if possible).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

Words for Summer: A Quiz

  • a closeup of a sunflower
  • Which of the following words means “of or relating to summer”?
Spell It

Can you spell these 10 commonly misspelled words?

Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!