Has a slightly stronger connotation than "temporary", sort of... extra-temporary, such that it only exists in a fleeting sense. Th term is also used in cryptogr

Has a slightly stronger connotation than "temporary", sort of... extra-temporary, such that it only exists in a fleeting sense. Th term is also used in cryptography: https://en.wikipedia.org/wiki/Ephemeral_key https://en.wikipedia.org/wiki/Ephemeral_key