pẹ̀tẹ́ẹ̀sì adj /k͡pɛ̀.tɛ́ɛ̀.sì/
Definitions
  1. upstairs, upper story of a building
    òkè pẹ̀tẹ́ẹ̀sì upper story
    ọ̀dẹ̀dẹ̀ pẹ̀tẹ́ẹ̀sì balcony
Etymology
Borrowed from English penthouse.
Source: Wiktionary, where this word is spelled “pẹtẹẹsi”. Reference: en-pẹtẹẹsi-yo-adj-bLFYoA-T