antepenultimate

/AE0 N T IH0 P EH0 N AH1 L T AH0 M AH0 T/
noun
  1. 1

    Two before the last in a series. e.g. (..., antepenultimate, penultimate, ultimate)

  2. 2

    The syllable that comes two before the last in a word.

    โ€œThe words animal, citizen, comedy, dangerous, obvious, and antepenultimate are stressed on the antepenultimate.โ€

adjective
  1. 1

    Two before the last, i.e., the one immediately before the penultimate, in a series.

    โ€œThis book has ten chapters โ€” chapter 8 is the antepenultimate one.โ€

Source: https://en.wiktionary.org/wiki/antepenultimate