SO

SO /S-O/ n.  1. (also `S.O.') Abbrev. for Significant
   Other, almost invariably written abbreviated and pronounced /S-O/
   by hackers.  Used to refer to one's primary relationship, esp. a
   live-in to whom one is not married.  See {MOTAS}, {MOTOS},
   {MOTSS}.  2. The Shift Out control character in ASCII
   (Control-N, 0001110).