极其重要；必不可少
to be the most important thing
In any of these discussions, of course, honesty is of the essence. 当然，在探讨任何问题时都必须坦诚。
Time is of the essence. 时间至关重要。
With this form of communication, speed is of the essence.
Some of our patients are already very sick, so time is of the essence.
When speaking in public, clear diction is of the essence.
See also: essence (IMPORTANCE)