Simoun is one of my favorite shows of the new season. The backgrounds, character design, mecha and music are all outstanding. As is most of the voice-acting, particularly that of Takahashi Rieko as the red-haired Neviriru. And the presence of Takahashi Mikako, Toyoguchi Megumi, Koshimizu Ami and Mamiko Noto (in two roles) doesn't hurt. The story, animation, and acting work together to make the characters and their emotions very effective, at least for me.
One thing stopping some people from enjoying the show is the unusual world it's set in and the special terminology that fills the dialogue. There is now a glossary of the terminology on the official site. Here is a translation of what's there so far, along with a short note about the world:
Two-seated aircraft of the nation of Simulacrum. Using the power of the Helical Moutoris engine passed down from ancient times in the temple of the theocracy of Simulacrum, they fly with great ease and freedom.
Shimire Simoun (abbr. Shimire)
Training craft for Simoun pilots. There are one- and two-seated versions.
A system passed down from ancient times for using the power of the Tempus Patium, which spreads a strange radiation over Simulacrum.
The deity worshipped by the faithful in Simulacrum. The Palace of the Tempus Patium holds the “Spring” which is the centre of religious worship in Simulacrum.
The pilot, who occupies the front seat of a Simoun.
The navigator, who occupies the rear seat of a Simoun. Also controls weapons.
The two-person team that (wo)mans a Simoun
The patterns drawn by the flight of a Simoun. Whole patterns and types of lines are both aspects of Ri Maajon. There are several hundred different patterns, but they can be combined in countless ways. They have been passed down from ancient times, but the meaning of many of them has been forgotten.
Suigyoku Ri Maajon [Emerald Ri Maajon]
The legend is that Sibylla who succeed in creating this Ri Maajon serve at the side of the Tempus Patium. [This is called the Jade Ri Maajon in the fansub.]
To practice Ri Maajon by wearing implements on the legs that show the patterns formed as you move. All the Sibylla like doing Maaju.
A big columnar space built through the bottom of the Prima ship [the main ship, where the Sibylla live].
The corps led by Neviriru, and of which Aaeru and the others are members.
The priestesses who ride the Simoun.
The top Simoun Sibylla: the “Golden Priestess.”
The leader of a corps.
Words in the glossary are transliterated directly from the Japanese on the official site, except for a few which I have converted into their English/Latin originals: Helical, Simulacrum, Corps, Pool, Tempest, Regina ("queen" in Latin), Auriga ("charioteer" in Latin), Sibylla. Sagitta (sajitta, the navigator and weapons officer of a Simoun) means "arrow" in Latin. Simoun is pronounced "shimoon" in Japanese.
The world is called Taikuuriku ("Sky Land"). There are two nations: the theocratic Simulacrum, and the Craftsman Nation overseas. The industrial Craftsman Nation keeps invading Simulacrum to try to gain the secret of the Simoun, which fly so much better than anything they can build.
On this world, at least in Simulacrum and probably elsewhere, people are all born female. At 17 Simulacrans wade into the holy pool, which turns them into adults and changes some of them into males. The pilots at least, and probably everyone, get to choose which sex they want to become. In Simulacrum, there are no males under 17 years old.