Adjective
1. urgently needed; absolutely necessary;
"a critical element of the plan""critical medical supplies""vital for a healthy society""of vital interest"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"3. full of spirit;
"a dynamic full of life woman""a vital and charismatic leader""this whole lively world"4. manifesting or characteristic of life;
"a vital, living organism""vital signs"