Jadzia and Ezri
Dax were two main characters in
Star Trek: Deep Space Nine. They were not family, but rather Trill who both served as hosts (one after the other) to a symbiont named
Dax. After joining with a symbiont, Trills take the name of their symbiont as a surname. I don't believe
Jadzia's birth surname was ever revealed, but Ezri was called Ezri Tigan before being joined.
Memory
Alpha's articles:
Jadzia Dax: http://memory-alpha.org/en/wiki/Jadzia_DaxEzri Dax: http://memory-alpha.org/en/wiki/Ezri_DaxDax symbiont: http://memory-alpha.org/en/wiki/Dax_%28symbiont%29
Besides the
ST reference,
Dax just sounds generically very sci-fi and trendily macho to me. So it's nmsaa.