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.
Important; serious; not trivial or petty.
Rigorous; severe; afflictive.
Heavy (“having a lot of weight”).