Angels

Usages of the word "Angel" in Neon Genesis Evangelion.

As most commonly used in NGE, the word "Angel" refers to any of Adam's 15 Children. However, Adam herself and Lilith are also described as Angels, the 1st and the 2nd. Some people have claimed that it means whatever Nerv and Seele want it to mean, but this seems a little cynical. Actually, the legitimate defination is: Any of the Seventeen semi-devine beings described in Seele's secret Dead Sea Scrolls, which were found in the White Moon and the Black Moon. In End of Evangelion, Misato Katsuragi describes man as the 18th Angel.

Adam's children

As stated above, the most common definition of Angel is "any of Adam's children". Unleashed from the white moon during Second Impact, the Angels were scattered about the Earth, (at least one ended up in orbit), and began a 15 year incubation period. At the time the series opens, Angels 3-17 have begun to attack Tokyo III. If any of them succeeds in reaching Adam or Lilith, mankind will be destroyed in a destructive Third Impact. It is the task of the Evangelion Units and their pilots to defeat the Angels. Both Gendo Ikari's and Seele's plans call for the destruction of the Angels.