plural cruxes also cruces ˈkrü-ˌsēz How to pronounce crux (audio)
: a puzzling or difficult problem : an unsolved question
The origin of the word is a scholarly crux.
: an essential point requiring resolution or resolving an outcome
: a main or central feature (as of an argument)
… he discarded all but the essential cruxes of his argument.Carl Van Doren

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In Latin, crux referred literally to an instrument of torture, often a cross or stake, and figuratively to the torture and misery inflicted by means of such an instrument. Crux eventually developed the sense of "a puzzling or difficult problem"; that was the first meaning that was used when the word entered English in the early 18th century. Later, in the late 19th century, crux began to be used more specifically to refer to an essential point of a legal case that required resolution before the case as a whole could be resolved. Today, the verdict on crux is that it can be used to refer to any important part of a problem or argument, inside or outside of the courtroom.

Examples of crux in a Sentence

the crux of the problem is that the school's current budget is totally inadequate
Recent Examples on the Web One crux for Spain’s independent sector is to attract investment, vital to sustain game development on more ambitious projects whose cost may not be covered by initial publishers’ deals. Callum McLennan, Variety, 17 Aug. 2023 The real crux of this is the husband and his attitude. Meghan Leahy, Washington Post, 19 July 2023 Camp life is an integral part of hunting, perhaps the very crux of the sport. Susan Casey, Field & Stream, 6 Dec. 2020 Standing 2,300 feet high, Polar Circus is considered to be one of the most classic ice climbs in the Canadian Rockies; a showpiece capped with it’s crux: a final two pitches that are a massive sheet of ice. Chris Van Leuven, Outside Online, 17 Feb. 2023 Again, misunderstandings abound, and the main crux of the story is, what just happened? Tim Moffatt,, 16 Dec. 2022 To be able to take that, process it, and then move forward — that's the whole crux of it. Patrick Gomez,, 18 Apr. 2023 The main crux of the dispute between the railroads and their workers revolves around time off rules. Matt Egan, CNN, 28 Nov. 2022 At the current crux of hard-cap avoidance for the Heat is the return to free-agency of Tucker. Ira Winderman, Sun Sentinel, 29 June 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'crux.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Latin cruc-, crux cross, torture

First Known Use

1718, in the meaning defined at sense 1

Time Traveler
The first known use of crux was in 1718


Dictionary Entries Near crux

Cite this Entry

“Crux.” Dictionary, Merriam-Webster, Accessed 4 Oct. 2023.

Kids Definition

plural cruxes also cruces ˈkrü-ˌsēz How to pronounce crux (audio)
: the most important point
the crux of the problem

from Latin crux "cross, torture, trouble" — related to cross, crucial, crucify

More from Merriam-Webster on crux

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