Enby
A non-binary person — from saying the letters N.B. out loud.
Enby comes from sounding out NB, the abbreviation for non-binary. It gives non-binary people a noun for themselves, the way woman and man work as nouns.
It reads as warm and informal. Plenty of non-binary people use it happily; others find it a little cute for their taste and prefer non-binary person. Both reactions are common, and neither is wrong.
One thing worth knowing: NB was already in long use as shorthand for non-Black in racial justice conversations, which is part of why the spelled-out enby caught on.