A Sentient or Sapient being. Particularly one which travels amongst and colonizes star systems. It's root suggests the word means: beings with the ability to communicate creatively, ala Sophistry.
The Vargr pirate barked an objection at the notion that prey species, such as the K'kree, qualified as Sophant beings...never mind that they colonized numerous worlds.
A relationship that is just so-fun! You can say two friends are in a Sophan if they're more than friends but not dating, just in between, being so fun.
Boy: Hey I like you but don't want to date you..
Girl: Well we can just be in a Sophan! That way we can just be in a complicated but fun ship!
Boy: Sounds like it's so-fun!