the act or fact of surviving, esp. under adverse or unusual circumstances.

a person or thing that survives or endures, esp. an ancient custom, observance, belief, or the like.

Anthropology . (no longer in technical use) the persistence of a cultural trait, practice, or the like long after it has lost its original meaning or usefulness.

of, pertaining to, or for use in surviving, esp. under adverse or unusual circumstances

survival techniques.

adjective

extant , leftover , remaining , residual , surviving , vestigial , viable

noun

continuation , endurance , natural selection , relic

verb

subsist , survive , weather