vital

adjective

1. 1

   Relating to, or characteristic of life.

   “vital energies; vital functions; vital actions”

2. 2

   Necessary to the continuation of life; being the seat of life; being that on which life depends.

   “The brain is a vital organ.”

3. 3

   Invigorating or life-giving.

4. 4

   Necessary to continued existence.

   “The transition to farming was vital for the creation of civilisation.”

5. 5

   Relating to the recording of life events.

   “Birth, marriage and death certificates are vital records.”

6. 6

   Very important.

   “It is vital that you don't forget to do your homework.”

7. 7

   Containing life; living.

8. 8

   Capable of living; in a state to live; viable.