Her bottom plate was not in, and her upper lip protruded; from time to time she would draw her nether lip to her upper plate and carry her chin with it.
There are no more uses of "nether" in the book.
Show samples from other sources
Intently he listened for any sound from the nether world...
James Matthew Barrie -- The Adventures of Peter Pan
...she could not bear a coarse word, so far as her limited vocabulary reached she had a passion for euphemisms, and she scented indecency everywhere; she never spoke of trousers but referred to them as nether garments...