"last syllable but one of a word or verse, a penult," 1580s, from Latin pænultima (syllaba), "the next to the last syllable of a word or verse," from fem. of Latin adjective pænultimus "next-to-last," from pæne "almost" (a word of uncertain origin) + ultimus "final" (see ultimate).
Pentecost
pentecostal
penthouse
Pentothal
penult
penultima
penultimate
penumbra
penurious
penury
Penzance