JAMS Club
What do all of the weird words mean?!
Anime (pronounced Ann-e-may)
Japanese animation. Also known as Japanimation
Fan Service
The term originally referred to scenes which were gloriously animated just for fan appeal.  It has come to refer to scenes with scantily (or not at all) dressed characters.
Fansub
A fan-subtitled production. This is the only way to find a translation of many less popular titles, as well as a few surprising ones like Rayearth. Often done with amateur equipment and/or unprofessional translation. Generally these are distributed by copying freely, so poor quality copies are common. It is unethical as well as illegal to fansub a show which is being commercially translated. It is also highly unethical to "bootleg" (sell for profit) fansubs.
Hentai (also etchi, "H")
Refers to sexually explicit material. Etchi is the Japanese pronunciation of the roman letter "H" (the first letter in the english writing of the word), and has come to connote the same meaning.
Hiragana ( Hiragana no character)
Japanese characters used for native words, as well as grammatical particles.  Each character corresponds to one syllable, so you can write the syllabic pronunciation of a kanji character if you'reunsure of its writing (or are lazy). A very common hiragana character in anime titles is "no", which means "of" or "belonging to". Although it doesn't look like it, hiragana characters are actually descended from Chinese writing. (see kanji)
Irasshaimase!
Welcome!
J-Pop (also see seiyuu)
Refers to Japanese popular music. The sound is somewhat unlike anything you have never heard before -- resembling English pop, but with a very distinct sound. A lot of anime shows use existing songs, and most every show has a soundtrack CD. It is even fairly popular for "image albums" or separate singles albums to be produced for a successful anime series. It is not uncommon for the voice actors to perform singing in the show's soundtrack.
Nihongo
(Japanese language)
Written in rather bad kanji
Kanji
Japanese characters directly based on Chinese writing. Most kanji characters have a specific meaning and several readings, unlike the later-developed hiragana and katakana characters which are are syllabic (making one sound).
Katakana
Japanese characters that are used to write words of foreign origin. Lots of anime titles (such as Escaflowne, actually written esukafurone) as well as fantasy-based words and names in anime and manga are written in katakana. Katakana was also developed based on Chinese writing.
Kawaii (pronounced Ka-y-ee)
An adjective meaning cute, it also refers to character designs (like Mokona) and art. The word in Japanese also has several other contextual meanings such as "dear to me" and even "you poor thing/person".
Magical Girl (Mahou Shoujo; also see shoujo)
Refers to a specific genre featuring young girls with some sort of magical power. Although the more action-oriented shows such as Sailormoon or Akazukin Chacha are more commonly associated with the term, perfectly harmless shows such as Hime-chan no Ribon and Kiki's Delivery Service also fit in this genre. Generally aimed at younger, female audiences.
Manga (pronounced Mon-ga)
Japanese literature like a comic book. Due to the traditional basis, most manga today is still produced in black-and-white.
m.i.
A somewhat standard unit used to measure exposure to Japanese Animation. It is equal to the length of watching the original Maison Ikkoku TV series, which varies between 40 and 48 hours depending upon interpretation (and VCR maintenance). Research is currently being done by the club to measure the effects of exposure and establish safe guidelines. So far, no upper limit has been determined, although ill effects, such as social stigma, can occur with dosages as low as 0.1 m.i over one day.  This term was first seen on the Banzai Anime Klub of Alberta (BAKA) home page.
Miyazaki
One of Japan's (and the world's?) most famous animators, Hayao Miyazaki. Having recently retired, he is generally considered to be one of the founders of modern Japanese animation.
Name Suffixes
In spoken Japanese, a suffix is generally attached to another's name in order to indicate a level of respect or formality. Sometimes (especially in fansubs) the subtitles will include these suffixes. Not using a name suffix could show intimacy, casualness, or perhaps that the characters are not Japanese!  Here is a brief explanation of commonly used suffixes:
-chan
Used for young children, pets, boyfriends or girlfriends. Diminuative
-kun
Generally used for young men in a rather casual manner. Could also be used to address in-group (ie. club members) regardless of gender.
-san
A very neutral and respectful form, similar to "Mr." or "Miss". Also generally used when addressing your parents / older siblings.
-sama
A very respectful form used to indicate humility by the user. Used to address a God, royalty, etc, or just to be extremely polite (ie. to customers).
senpai
Used when referring to another student, club member, etc, who is your senior.
sensei
Refers to a respected professional such as a doctor, teacher, or lawyer.
People normally does not use a name suffix when referring to themselves!  However, small children might use their name with chan when talking about themselves.
OAV / OVA
Stands for "Original Animation Video" or "Original Video Animation". Refers to an anime series released directly to for home video. Generally, these are shorter than TV series, often only running three or four of episodes per series. Examples of OVAs are Bubble Gum Crisis, Oh My Goddess!, and Iria.
Roomaaji (also Romanji)
A way of transliterating Japanese pronunciations using roman characters (like English uses). There probably is a standard established somewhere, but we haven't figured it out. For example, the romanji writing of the katakana characters used to write "Escaflowne" is "e su ka fu ro o ne".
SD (Super-Deformed)
An art style using greatly exaggerated proportions of characters, used generally for comic or sometimes kawaii effects. Shows like Magic Knights Rayearth, Rurouni Kenshin, and Sailor Moon use this a lot.
Seiyuu
A Japanese voice actor or actress, who is sometimes also a singer. Popular seiyuu include Aya Hisakawa, Megumi Ogata, Kikuko Inoue, Megumi Hayashibara, and many, many others.
Shounen
Literally means "boy", shounen anime / manga refers to anime or manga aimed for boys, like Dragon Ball and Rurouni Kenshin.
Shoujo
Literally means "girl", shoujo anime / manga means anime or manga for girls, like Sailormoon and Magic Knights Rayearth.
Tezuka
Osamu Tezuka was one of the first successful animators in Japan.  His works include Testuwan Atomu (Mighty Atom, also known as Astroboy to English audiences), Jungle Emperor (Kimba the White Lion), and Hi no Tori (Bird of Fire), as well as numerous artistic and experimental films.