The Charm of English: Crucial

CRUCIAL   adjective  /ˈkruːʃ(ə)l/

    1.something that is crucial is extremely important because it has a major effect on the result of something

    crucial for:                The money is crucial for the research.

    crucial to:                 Resolving this issue is crucial to making peace work.

    it is crucial (that):      It is crucial that all students develop these basic skills.

    

    2

    British (very informal)           extremely good.

You can hear crucial  here (The Devil Wears Prada):