1 have a place as part of objective reality.
2 a have being under specified conditions. b (foll. by as) exist in the form of.
3 (of circumstances etc.) occur; be found.
4 live with no pleasure under adverse conditions (felt he was merely existing).
5 continue in being; maintain life (can hardly exist on this salary).
6 be alive, live.
Etymology: prob. back-form. f. EXISTENCE; cf. LL existere
Useful english dictionary. 2012.