Most common and some not common. They could mean different things in different fandoms, but here are definitions in my own words, as I interpret them. If there are some words you've seen around that aren't listed here, feel free to email me at [email protected], but be sure to title the subject like "ficdict" or else it's liable to get deleted. :)
Angst
Sad element in a fanfiction
A/N
Stands for Author(ess) Notes. Usually quirky, and should usually be read.
AU/AU
Alternate Universe
Bash
I.E. "slight Anzu-bashing", where Anzu is made fun of or mistreated in the fanfiction for one reason or another. Generally mistreatment.
Beta/Beta reader
Person who beta-reads a fanfiction, much like beta testing.
Canon
Something that happens IN the series of the fandom the fic is being written for
Con
Short for convention. I.E. Sakura-con
Crossover/X-over
A fanfiction that uses more than one fandom in its plotline.
Disclaimer
Claiming no right to the anime/manga/TV show the fic is being written for and do not make money off writing fanfiction. Sometimes merged into A/N
Drabble
Fanfiction with 100 words or less, no clear plot, just an idea or scene
Ep.
Short for episode
Fanfiction
Also fic, fanfic; If you don't know what this is, you shouldn't even be here.
Fanon
Detail from fandom that is not canon but is generally accepted my many of the fans. I.E. InuYasha biting Kagome on the juncture of her neck and shoulder being the mating mark.
Femslash
Also F/F; Female/Female relationships; also Yuri
Flame
A "review" with no critisizm but pure senseless bashing of the fic
Fluff
"mushy stuff"; senseless romance
H/C
Hurt/Comfort; Character A is hurt in some way and needs comfort, which Character B provides.
Jossed
Disproven and/or done differently in canon, that was not canon when the fic was written. I.E. If InuYasha were to choose Kagome in a fanfiction but choose Kikyou later in canon after the fanfiction had already been written, that has been jossed. Also, To Be Jossed. (Origins from Buffy the Vampire Slayer fandom?)
M/M
Stands for Male/Male relationships; also Yaoi
Mary Sue
Also Gary Stu (male version of the following); A female original character that is any of the following without flaws: amazingly perfect, amazingly beautiful, unusual eye/hair colors, amazingly talented, gifted musically/magically, tragic past, related to/romantically involved with a canon character, dies tragically in the arms of a canon character. Several theories on the origin, but all leading back to Star Trek
N/C
Nonconsensual; rape warning
OC
Original Character; character not canon and created by the author
OOC
Out Of Character; 'nuff said. Like InuYasha being a total pushover or being totally mushy, or Heero being emotional without plot-backed reason.
POV
Point Of View; 'nuff said
PTB
Powers That Be; owners/creators of the canon series/movie the fanfiction is written for
PWP
Plot What Plot?; Porn Without Plot
Rating
Done in fiction ratings or movie ratings. Fiction (and video games) I.E. E, T, M, X. Movie I.E. G, PG, PG-13, R, NC-17. Fiction/Game ratings becoming more common than movie ratings for fanfiction
Slash
Same-gender relationships, usually male
Songfic
Inspired by a song, incorporating the lyrics into the fic. Can be very badly done if not done correctly.
Spoilers
Spoiling something that happens in canon. Do I really have to define this one?
WAFF
Warm And Fuzzy Feelings; cute, romantic themes; also fluff