crucial

Meaning

1. Essential or decisive for determining the outcome or future of something; extremely important; vital.
2. Cruciform or cruciate; cross-shaped.
3. (slang) Very good; excellent; particularly applied to reggae music.

Hyphenated as

cru‧cial

Pronounced as (IPA)

/ˈkɹuː.ʃəl/

Etymology

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”).
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.