iris is the visible arc described around a throne and upon an angel's head.

The term denotes a visible arc-like feature in two visionary descriptions: around the throne in Revelation 4:3 and upon the head of an angel in Revelation 10:1.

1. Visible arc in visionary descriptions · dominant

   In Revelation 4:3, the nominative singular feminine form occurs in the description of an arc around the throne; the APB renders the clause "and a rainbow around the throne was like an emerald in appearance." In Revelation 10:1, the same form occurs in the description of the descending angel, and the APB renders it "and the rainbow upon his head."

   Revelation 4:3Revelation 10:1

In the Anselm Project Bible: The APB presents the term as "rainbow" in both verses, describing it around the throne in Revelation 4:3 and upon the angel's head in Revelation 10:1. The verse is read as a whole.