Japanese Words

anime	Litterally means "animation". In Japan, any animated film is considered anime. Outside of Japan, the word on it's own has come to refer exclusively to Japanese animation.
bishoujo	Litterally means "beautiful young girl"
bishounen	Litterally means "beautiful young boy." The translation is commonly written as beautiful boys/men, or pretty boys. The art of being bishounen is more than just looking beautiful. It is usually always followed by at least one of the following narcissism, egotism, long hair, charisma. Other traits that are not always associated with bishonen are homosexuality, feminine behavior and qualities, feminine forms of speech.
cosplay	Combines the words from "costume play" which refers to dressing up as anime characters.
doujinshi	Amateur-created manga that often, but not always contain adult content
gengashuu	Litterally means "artbook".
henshin	Litterally means "transform".
hentai	Litterally means "pervert, perversion, abnormal". Hentai refers to anime or manga of pornographic nature. It does NOT mean nudity.
jun-ken-pon	Rock, Paper, Sissors. And a tie turing junken-pon is 'aiko-de-cho'.
manga	Litterally means "comic, cartoon". In Japan, any comic is considered manga. Outside of Japan, the word on it's own has come to refer exclusively to Japanese comics.
manga-ka	Litterally means "comic artist".
miko	Litterally, a miko is a "priestess", usually of a Shinto shrine. In anime, a miko does not always have to be associated with the Shinto religion, but rather a priestess in general. [ie. Fushigi Yuugi]
OAV, OVA	Original Animation Video or Original Video Animation. Basically, these are anime that go straight to video. It is not shown on TV or at the movie theater.
seiyuu	This term refers to voice actors and actresses.
seramyu	Combines the words from "sailormoon musical" which refers to the live action, on stage shows of Pretty Soldier Sailormoon.
settei shiryoshuu	Materials Collection book.
shitajiki	Pencil boards.
shounen ai	This term means "boy's love". It refers to a less agressive form of yaoi.
tankoubon	Collected volumes of previously published manga chapters [it is equivelent to an american graphic novel].
yaoi	Abbreviation for the phrase "no peak, no point, no meaning". It refers to anime or manga featuring elegantly drawn male/male couplings where there is no real story within the erotism.
yuri	Litterally means "lily" as in the flower. It is meant to represent a female. It has come to mean anime or manga featuring female/female couplings.

English Words

fan art	Art based on an existing anime or manga drawn by fans.
fan dubs	Voiced over into the English [or whatever other language] anime produced by the fans.
fan fic fan fiction	Stories based on an existing anime or manga written fans and usually posted online for others to read.
fan subs	Anime subtitled into another language, produced by fans rather than a company. Subtitles are written dialogue placed at the bottom of the screen while watching the video