Crucial Definition

kro͝oshəl

adjective

Of supreme importance; decisive; critical.

A crucial decision.

Webster's New World

Extremely significant or important.

American Heritage

Vital to the resolution of a crisis or the determination of an outcome.

A crucial moment in the political campaign.

American Heritage

Having the form of a cross.

A crucial incision.

Webster's New World

Being essential or decisive for determining the outcome or future of something; extremely important.

The battle of Tali-Ihantala in 1944 is one of the crucial moments in the history of Finland.

A secure supply of crude oil is crucial for any modern nation, let alone a superpower.

Wiktionary

Synonyms:

Antonyms:

Origin of Crucial

The meaning “decisive, critical” is extended from a logical term, Instantias Crucis, adopted by Francis Bacon in his influential Novum Organum (1620); the notion is of cross fingerboard signposts at forking roads, thus a requirement to choose. Specific quote is:

From Wiktionary
From New Latin (īnstantia) crucis, (experīmentum) crucis crossroads (case), crossroads (experiment) from Latin crux cruc- cross Sense 2, French from Old French from Latin crux

From American Heritage Dictionary of the English Language, 5th Edition
1706, from French crucial, a medical term for ligaments of the knee (which cross each other), from Latin crux, crucis (“cross”) (English crux), from the Proto-Indo-European *(s)ker- (“to turn, to bend”).

From Wiktionary