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lubber's line

American  
Or lubber line

noun

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  1. a vertical line on the forward inner side of the bowl of a fixed compass, used as a reference mark indicating the heading of a vessel.

Etymology

Origin of lubber's line

First recorded in 1855–65

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The lubber's line was a point west of north.

From The Airship "Golden Hind" by Westerman, Percy F. (Percy Francis)

You observe that the thoughtful Polton has stuck a piece of thread on the glass of the compass to serve as a lubber's line.

From The Mystery of 31 New Inn by Freeman, R. Austin (Richard Austin)

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.