Gíẹ́sì name /ɡí.ɛ́.sì/
Definitions
  1. a historic monarch, or Ọ̀ọ̀ni, of the Ifẹ̀ kingdom historical
  2. one of the four ruling houses of Ifẹ̀, consisting of descendants of Gíẹ́sì broadly
Etymology
Probably from a Contraction or a nickname.
Source: Wiktionary, where this word is spelled “Giẹsi”. Reference: en-Giẹsi-yo-name-0TKGOEMn