vital (
http://definr.com/vital)
adj 1: urgently needed; absolutely necessary; "a critical element
of the plan"; "critical medical supplies"; "vital for
a healthy society"; "of vital interest" [syn:
critical]
2: performing an essential function in the living body; "vital
organs"; "blood and other vital fluids"; "the loss of
vital heat in shock"; "a vital spot"; "life-giving love
and praise" [syn:
life-sustaining]
3: full of spirit; "a dynamic full of life woman"; "a vital and
charismatic leader"; "this whole lively world" [syn: {full
of life},
lively]
4: manifesting or characteristic of life; "a vital, living
organism"; "vital signs"