1. Of, relating to, or characteristic of life: See synonyms at living.
2. Necessary to the continuation of life; life-sustaining: a vital organ; vital nutrients.
3. Full of life; animated: "The population of the teeming, vital slum . . . declined" (Rick Hampson).
4. Imparting life or animation; invigorating: the sun's vital rays.
5. Necessary to continued existence or effectiveness; essential: "Irrigation was vital to early civilization" (William H. McNeill). "A vital component of any democracy is a free labor movement" (Bayard Rustin).
6. Concerned with or recording data pertinent to lives: vital records.
7. Biology. Used or done on a living cell or tissue: vital dyes; vital staining.
8. Destructive to life; fatal: a vital injury.

[Middle English, from Old French, from Latin vītālis, from vīta, life.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.