Let's break it down:
* Te: The definite article, like "the" in English.
* Kopua: This word has a few meanings, including "rainbow" or "arch." In this context, it refers to the rainbow.
* Rangi: This word means "sky" or "heaven."
Therefore, "te kopua rangi" specifically refers to the rainbow as a celestial phenomenon. It's a beautiful and poetic way to describe this colorful arc in the sky.