antepenultimate

adj

1. (not-comparable)Two before the last, i.e., the one immediately before the penultimate, in a series.

   “This book has ten chapters — chapter 8 is the antepenultimate one.”

   “[…] they [the sounds of an echo] next strike the ultimate secondary object, then the penultimate and antepenultimate; […]”

noun

1. The second before the last in a series; the item preceding the penultimate and ultimate.
2. The syllable that comes two before the last in a word.

   “The words animal, citizen, comedy, and antepenultimate are stressed on the antepenultimate.”