Sammich

1. Pet name used by fans to refer to Sam Winchester.

Use of the name (in canon): The name isn't used on the tv-show (as of the end of Season 4), but it has appeared on more than one occasion in Keith R.A. DeCandido's tie-in novel Nevermore by Dean as a nickname/pet name for Sam.

2. A "Sammich" sometimes also means a threesome including two Sam Winchesters (e.g. Sam/Sam/Dean). A Sammich can be achieved by writing a time-travel story or a fic in which a doppelganger appears.