1)Adjective, popular culture; A term of endearment signifying that one is so coveted as to inspire jealousy among the gods of beauty, fertility, and love.
Eg: "You are my world, Miss Kallisti."
Or, as in correspondence, "Dearest Kallisti,"
2) Adverb, Greek ; literaly translated, "to the most fair."
3) In Greek mythology; Upon learning that she was the only diety who was not invited to the marriage of two gods, the goddess Eris
inscribed "Kallisti" onto a golden apple, which she then tossed into the wedding reception of gods. The ensuing quarrel over possesion of the golden apple, between Hera, Athena, and Aphrodite, eventually culminated in the Trojan war.
In literary works; "The Illuminatus Trilogy," by Shea and Wilson.