Uncanny is the right word for her: from the German unheimliche, uncanny means the opposite of what is familiar, the flipside of home. We use the term to describe something that is supernatural or eerie, but the root of it contains a duality--it connotes an object or experience that is both foreign and intimately recognizable at the same time. Dejà vu can be an uncanny experience; we think "I've never been here before" but "somehow, I've been here before."
Lilith is like that, since she is not named in the biblical text of Genesis, but haunts our tradition nonetheless. Absent more than present, she is a great instance of how what is not said in the text can generate as many meanings as what is said.
She is also intrinsically Jewish--a combined product of scholarly exegesis and folkloric superstition. As Aviva Cantor Zuckoff put it in a seminal 1976 article reclaiming Lilith: "No non-Jewish source tells of a female struggle for equality or gives it as a reason for the vengeful behavior of a female demon. This is especially important to us in exploring how the Lilith myth connects with our unique history."
This coming Shabbat, the day after Simhat Torah, when we roll the Torah scroll back to the beginning, to begin the beginning again, we'll read Genesis 1, from which Lilith derives. All through Genesis, we are presented with alternate branches of the family tree--Lot, Ishmael, Esau--the other side of the family that is related to us, but is not us. As Adam's co-creation, woman before Eve, Lilith is the first instance of this concept of the road not taken, the shadowy counterpart, the unspoken alternative.
Reading "In the beginning..." and "Let there be..." and "it was good..." all for the umpteenth time, can we not be lulled by the familiarity of the passage, but rather look at it from the perspective of the uncanny? Where is the shock of the strange? How can it be a signpost of forgotten possibilities?