crucial

Decisive and of the utmost importance; critical to the success or failure of something.

• crucially/ˈkruːʃəli/(adv)至关重要地

• crucial role
• crucial decision
• prove crucial
• crucial moment
• crucial evidence
• crucially important
• at a crucial time

1. 1.Communication will be crucial during the transition — people need to know what's happening and why.
2. 2.The support of the local community proved crucial to the project's eventual success.

• critical/ˈkrɪtɪkəl/— extremely important at a decisive moment
• vital/ˈvaɪtəl/— absolutely necessary
• pivotal/ˈpɪvətəl/— of critical importance for the outcome

from Latin "crucialis" = of the cross — early scientists used crossroads-shaped symbols to mark decisive experiments; a "crucial experiment" was one that decided between theories