Acting Normal - Completely speechless or screaming uncontrollably, in the presence of Robert Pattinson, the the point, he can only laugh and run his fingers through his hair.   

Angward- (angry Edward) Edward losing his cool demeanor and acting more vampire-like. 
Bedward-Edward Cullen in bed scenes of the Twilight movies.
Bellward-A reference to Bella and Edward.
Carlizzle - Peter Facinelli’s nickname for Carlisle.  (He said this at a Twilight convention).
Cullenitis - (itis= inflammation) an ever growing desire to become a member of the Cullen Family. 
Eddie - A goofy nickname for Edward Cullen.
Fan Fiction - Stories written by fans with the characters from the books put in different or alternative scenarios.
Finger Porn - Photos or videos of Rob's hands showing his fingers in various poses. 
FF - Fan Fiction.
The Goddess - The creator of the Twilight Saga, Stephenie Meyer.
HOBO Love - (per urbandictionary.com ) The bromance between actors Robert Pattinson and Tom Sturridge 
It's Time. - (Alice quote from Twilight) Used when anything Twilight related is approaching. 
JawPorn - The beautiful sexiness of Rob's strong jaw line. Strong features is a very true Edward trait. 
Krisbian - A girl that is straight, but that would go gay for Kristen Stewart.  A girl crush of Kristen.
KStew - Referring to Kristen Stewart.
Lemon - smut in a FF story.
MamaStew - Kristen's real life mom.
Marshmallow - Someone who isn’t a “real” man and can't handle seeing a gory movie (“What a  marshmallow” Jacob quote from New Moon).
MOTU - Acronym for the Twilight fanfiction "Master of the Universe".
Ninja Stew - Kristen Stewart in underground mode and making traveling with zero paparazzi photos surfacing.
Nonsten - (No Robsten) Fans who don’t believe in a romantic relationship existing between Robert Pattinson and Kristen Stewart.  Anti-Robsten.
OCD-OTD - Obsessive Cullen/Twilight Disorder.
OMT / OME / OMJ / OMB - Oh My Twilight / Edward / Jacob/ Bella (replacement for “oh my God”).
Papa Stew - Reference to Kristen Stewart's real dad.
Papa Swan - Reference to Bella's dad in the Twilight moives.
Pfach - Peter Facinelli's self proclaimed shorter name (to be like RPattz).
The Pretty - Referring to Robert Pattinson cause he is so pretty/beautiful.
Robalicious - anything scrumptiously related to Robert Pattinson.
Robsessed - someone obsessed with Robert Pattinson.
Robsten - A reference to Kristen Stewart and Robert Pattinson, specifically implying a romantic connotation.
Robstenation - (Robsten nation) Fans all over the nation loving/obsessing over the romantic relationship of Kristen and Robert.
RPattz or RPatz - Referring to Robert Pattinson.
Set Stalker/soldier - someone who visits the movie sets and/or shares all their findings.
Sex hair - due to Robert Pattinson's unruly, unbrushed locks this is a nickname for him.
Sex hair - (male definition) Kristen Stewart's hair in certain portions of Twilight.
Sex on legs - due to Robert Pattinson's long legs, this is a nickname for him.
Spunk Ransom - Robert Pattinson’s self proclaimed nickname (per a 2008 MTV interview).
Taysten - Reference to Taylor and Kristen together.
Tay Tay - Nickname for Taylor Lautner.
Team Fire + Ice - a.k.a. Team Renesmee - When you are routing for the little nudger.
Tent City - An area where fans camped out for the Eclipse premiere at Nokia in LA Live in 2010.
Twibrary - A place where several Twilight related fanfictions are accessible.
Twerd (Twilight Nerd) - a super fan of Twilight that knows tons of information.
Twi-holic - one who exhibits an obsessive need for or interest in Twilight.
Twigasm - The feeling of unadulterated bliss that comes from experiencing Twilight.
Twigeek - someone equally obsessed with Twilight, but better informed that a Twinerd.
Twiguy - A guy who has actually read the books.  They are rare, but yes, they do exist.
Twihard - an obsessive, over the top, Twilight fan.  This fan takes Twilight to the extreme.
Twilight Trinity or The Trinity - The three big Twilight stars.  Kristen Stewart, Robert Pattinson, and Taylor Lautner.
twija-vu - (deja-vu) The feeling that something happening to you or around you is just like something in the Twilight movies.  (This situation is giving me twija-vu).
Twissues - (tissues) Extremely sad parts of the Twilight books or movies, twissues might be needed.  
Twitreasure - after a shopping trip hunting for great Twilight merchandise.  What you find is Twitreasure.
WTH - What The Hale, instead of Hell (Can also be phrased “Oh Hale No!”).