darkcaverneyed

Most likely refers to the dark, often bluish-black, periorbital circles one gets under their eyes. While these circles are often thought to be a result of tiredness or lack of sleep, one’s susceptibility is also genetic.

While there’s no recorded definition for “darkcaverneyed” we know that Faulkner uses the word to describe Hightower’s physicality while talking to Byron about how to move forward with Lena. It's interesting to think of Hightower's relationship to both exhaustion and genetics, given his position as outsider within the town and his obsession with his grandfather's past.

//He speaks now with a kind of spurious brusqueness which, flabbyjowled and darkcaverneyed, his face belies// (LIA 306).