ọ́síjìn noun /ɔ́.sí.d͡ʒĩ̀/
Definitions
  1. oxygen (chemical element, O, atomical number 8)
Etymology
Borrowed from English oxygen.
Source: Wiktionary, where this word is spelled “ọsijin”. Reference: en-ọsijin-yo-noun-bmmycLl6