- involving an extremely important decision or result; decisive; critical: a crucial experiment.
- severe; trying.
- of the form of a cross; cross-shaped.
Origin of crucial
SynonymsSee more synonyms for on Thesaurus.com
Examples from the Web for crucial
All it needs is one more “pipe” to select and transmit the crucial information.Red Tape and Black Boxes: Why We Keep ‘Losing’ Airliners in 2014
December 29, 2014
Some pilots consider the infrared marker to be crucial to the close air-support mission to support ground troops.Newest U.S. Stealth Fighter ‘10 Years Behind’ Older Jets
December 26, 2014
And some of the most compelling statements came from a powerful, crucial set of equality allies: corporations.Corporations Are No Longer Silent on LGBT Issues
December 24, 2014
From the looks of it, mistletoe is a keystone species and plays a crucial role in that forest ecosystem.Mistletoe is the Vampire of Plants
December 21, 2014
Given that crucial importance, The Macallan is famously hands-on when it comes to its wooden barrels.How Much Do Whisky Casks Really Affect Taste?
December 10, 2014
Orley slapped his card down; it was a crucial card, the jack.Goodbye, Dead Man!
Tom W. Harris
But at any rate, no one will deny that interest is the crucial matter.A Writer's Recollections (In Two Volumes), Volume II
Mrs. Humphry Ward
What names will afford the most crucial test of natural fitness?Cratylus
Mrs. Winthrop helped him by her entrance at this crucial point.David Dunne
Belle Kanaris Maniates
The following and last experiment that I tried on this occasion was the most crucial.Telepathy
W. W. Baggally
- involving a final or supremely important decision or event; decisive; critical
- informal very important
- slang very good
Word Origin and History for crucial
1706, "cross-shaped," from French crucial, a medical term for ligaments of the knee (which cross each other), from Latin crux (genitive crucis) "cross" (see cross (n.)). The meaning "decisive, critical" (1830) is extended from a logical term, Instantias Crucis, adopted by Francis Bacon (1620); the notion is of cross fingerboard signposts at forking roads, thus a requirement to choose.