crux

Merriam-Webster's Word of the Day for June 2, 2026 is: crux • KRUKS  • noun Crux refers to the most important part of something (such as a problem, issue, or puzzle). It is often used in the phrase "the crux of." // The crux of the problem is that the project's budget is totally inadequate. See the entry > Examples: "The new trees number in the thousands. ... What will become of this nursery in the wild in the next hundred years, or thousand, is the crux of a scientific and policy dispute. Starkly different visions of how the grove will recover in the long run have implications on how forest managers should act today." — Doug Smith, The Los Angeles Times, 15 Mar. 2026 Did you know? Latin speakers used crux to refer 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. When English speakers adopted crux in the early 18th century, they used it to mean "a puzzling or difficult problem." In the late 19th century, crux developed a more specific use referring 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.