[1] : The Collaborative International Dictionary of English v.0.48

vital \vi"tal\, a. f., fr. l. vitalis, fr. vita life; akin to
   vivere to live. see vivid.
   1. belonging or relating to life, either animal or vegetable;
      as, vital energies; vital functions; vital actions.
      1913 webster

   2. contributing to life; necessary to, or supporting, life;
      as, vital blood.
      1913 webster

            do the heavens afford him vital food? --spenser.
      1913 webster

            and vital virtue infused, and vital warmth.
                                                  --milton.
      1913 webster

   3. containing life; living. "spirits that live throughout,
      vital in every part." --milton.
      1913 webster

   4. being the seat of life; being that on which life depends;
      mortal.
      1913 webster

            the dart flew on, and pierced a vital part. --pope.
      1913 webster

   5. very necessary; highly important; essential.
      1913 webster

            a competence is vital to content.     --young.
      1913 webster

   6. capable of living; in a state to live; viable. r.
      1913 webster

            pythagoras and hippocrates . . . affirm the birth of
            the seventh month to be vital.        --sir t.
                                                  browne.
      1913 webster

   vital air, oxygen gas; -- so called because essential to
      animal life. obs.

   vital capacity physiol., the breathing capacity of the
      lungs; -- expressed by the number of cubic inches of air
      which can be forcibly exhaled after a full inspiration.

   vital force. biol. see under force. the vital forces,
      according to cope, are nerve force neurism, growth force
      bathmism, and thought force phrenism, all under the
      direction and control of the vital principle. apart from
      the phenomena of consciousness, vital actions no longer
      need to be considered as of a mysterious and unfathomable
      character, nor vital force as anything other than a form
      of physical energy derived from, and convertible into,
      other well-known forces of nature.

   vital functions physiol., those functions or actions of
      the body on which life is directly dependent, as the
      circulation of the blood, digestion, etc.

   vital principle, an immaterial force, to which the
      functions peculiar to living beings are ascribed.

   vital statistics, statistics respecting the duration of
      life, and the circumstances affecting its duration.

   vital tripod. physiol. see under tripod.

   vital vessels bot., a name for latex tubes, now disused.
      see latex.
      1913 webster
see also:
vivid vital air vital capacity vital force force vital functions 
vital principle vital statistics vital tripod tripod vital vessels 
latex 

[2] : WordNet (r) 2.0

vital capacity
     n : the maximum amount of air that can be exhaled after a
         maximum inhalation usually tested with a spirometer;
         used to determine the condition of lung tissue

Vital Capacity >> V Words
Vital Capacity, definition of term: Vital Capacity
vital+capacity_pag1.html

Vital >> V Words
Vital, definition of term: Vital
vital_pag1.html

Capacity >> C Words
Capacity, definition of term: Capacity
capacity_pag1.html

Vital Principle >> V Words
Vital Principle, definition of term: Vital Principle
vital+principle_pag1.html