Okay--still moving along slowly through The Satanic Verses, and have come across this word twice. I would have said that it meant something like 'haunted' or related to the spirit world, but I think I came across the phrase, 'revenant spirits', which would seem to be a bit redundant. Shall we see?
Well, it's related.
One who returns after a lengthy absence. Which would make a phrase of Rushdie's like 'the revenant tide' make sense.
One who returns after death. Which would make my own understanding of the word comprehensible.
What strikes me now is that though these are two very different experiences, we can sometimes conflate the two, so that the unexpected appearance of someone long absent can feel like someone returning from the spirit world.
I've had that experience recently.