Being very important, or key to something.
Having or containing the centre of something.
Being in the centre.
Exerting its action towards the peripheral organs.
centre
Very important.
Invigorating or life-giving.
Containing life; living.
Necessary to continued existence.
Necessary to the continuation of life; being the seat of life; being that on which life depends.
Capable of living; in a state to live; viable.
Relating to the recording of life events.
Relating to, or characteristic of life.