Vital
/ˈvaɪt̬əl/
adjective
Relating to, or characteristic of life.
“vital energies; vital functions; vital actions”
Necessary to the continuation of life; being the seat of life; being that on which life depends.
“The brain is a vital organ.”
Invigorating or life-giving.
Synonyms: crucial, necessary, significant, extant, kicking, live, lifely