Capable of living; born alive and with such form and development of organs as to be capable of living; -- said of a newborn, or a prematurely born, infant.
- Capable of living, developing, or germinating under favorable conditions.
- Capable of living outside the uterus. Used of a fetus or newborn.
- Capable of success or continuing effectiveness; practicable: a viable plan; a viable national economy. See Synonyms at possible.