(1):

(v. i.) To be as a fact and not as a mode; to have an actual or real being, whether material or spiritual.

(2):

(v. i.) To live; to have life or the functions of vitality; as, men can not exist water, nor fishes on land.

(3):

(v. i.) To be manifest in any manner; to continue to be; as, great evils existed in his reign.