"Lilin" (katakana: リリン; Hebrew: לילין) is the term that the Angel Kaworu Nagisa uses to refer to humanity – or, more specifically, the species Homo sapiens. Since the Evangelion universe employs a more expansive conception of "humanity", "Lilin" is often utilized by fans to minimize ambiguity in certain contexts.
Mankind is the designated 18th Angel, as revealed by Misato Katsuragi in Episode 25'. They are a variation of humanity that arose from Lilith and possesses the Fruit of Knowledge, contrasted with Adam’s children, who possess the Fruit of Life. While Adam’s children possess individuated forms and are segregated into separate “Angels” (despite comprising a single race of entities), the billions of individual humans are treated as a single “Angel”, described as “a colony of flawed and separate entities”. Although never directly stated in the show, "Lilin" may be H. sapiens’ official “Angel” designation (going by SEELE’s list). For the sake of practicality, it will be treated as such from this point forward.
An ancient race of progenitor aliens termed the "First Ancestral Race" seeded life throughout the galaxy billions of years ago by spreading beings known as "seeds of life" to many worlds. Although they were never meant to co-exist, billions of years ago Lilith landed on Earth some time after Adam did. When Lilith arrived she spread the primordial ooze, LCL (actually, Lilith's own blood) which eventually evolved into the first single-celled life on Earth and ultimately, Homo sapiens. Thus Lilith is the direct progenitor of humanity.
Mankind received from Lilith the "fruit of Knowledge" as opposed to the Angels who benefited from the "Fruit of Life" (the S² Engine, the source of their power and regenerative capabilities). Thus, humans and Angels are incompatible. Still, as Adam came here first, Adam and Lilith were both created by the First Ancestral Race, Angels are no more "alien" to Earth than are humans.
In Evangelion 3.0 Kaworu mentions a death instinct that has been programmed into the Lilin since the beginning. This desire for death is what leads mankind to always attempt the Human Instrumentality Project. He also refers to Gendo as "King of Lilin". Asuka seems to be aware of the term, as she mentions it during the movies last scenes to refer to a place "where the Lilin are", probably to refer to the place where Misato and the WILLE crew landed.
- The word “Lilin” originates from Mesopotamian lore, referring to succubae. From their name may have issued the name of Lilith. According to Judaic lore, she is Adam's outcast first wife who was created "at the same time and from the same earth as Adam" as opposed to Eve, who is born of Adam's rib. 
- A Romanized rendition of リリン (Ririn) is not provided in the show or known from any official sources. Discrepancies exist in the localizations, since ADV (TV series) render it as "Lilim", whereas Manga Entertainment use "Lilin". Rebuild, although a separate canon from the TV series, uses "Lilin" in the first movie's preview for Evangelion 2.0, and so should be considered the "official word" on the matter.
- Whether any of the extinct species of hominids qualified as “Lilin” is entirely unknown and, perhaps, entirely unimportant.
- Episode 25’. Misato: “Shinji, we humans were born from a being called Lilith, who is a source of life just like Adam. We are the 18th Angel.” Translation by Bochan_bird.
- Episode 25’. Misato: “Having reached its limit as a colony of flawed and separate entities, humankind is to be artificially evolved into a perfect single being.” Translation by Bochan_bird.
- A preliminary draft for Episode 25’ actually has Misato say, “The 18th Angel remaining in the end is mankind. The Angel called Lilin, born from Lilith, who is like Adam.” The “Lilin” reference was edited out for reasons unknown.
- Learn Religions — The Legend of Lilith: Adam's First Wife
|Seeds of Life & Angels|
|In Neon Genesis Evangelion||Adam • Lilith • Sachiel • Shamshel • Ramiel • Gaghiel • Israfel • Sandalphon • Matarael • Sahaquiel • Ireul • Leliel • Bardiel • Zeruel • Arael • Armisael • Tabris • Lilin|
|In the manga||Adam • Lilith • Sachiel • Shamshel • Ramiel • Gaghiel • Israfel • Sahaquiel • Bardiel • Zeruel • Arael • Armisael • Tabris • Lilin|
|In Rebuild of Evangelion||Adams • First Angel • Second Angel Lilith • Third Angel • Fourth Angel • Fifth Angel • Sixth Angel • Seventh Angel • Eighth Angel • Ninth Angel • Tenth Angel • Twelfth Angel • Thirteenth Angel|
|In Proposal||Shateiel • Turel|
|In The NERV White Paper||Baraqijal • Iblis|
|In Decisive Battle in Tokyo-3||Adovaquiel • Atalibu • Azrael • Zefon|
|In First Impression||Unnamed Angel|
|In Second Impression||Insubstantial Angel|
|Other||Diemay Angel • Kingshitoel|