IPA: //ˈsʌnruːf//
KK: /ˈsʌnˌruf/
A part of a car's roof that can be opened to let in light and air.
On sunny days, I love to drive with the sunroof open.
Sunroof → It is formed from "sun" (from Old English "sunne", meaning the star that provides light and warmth) and "roof" (from Old English "hrof", meaning the top covering of a building). The word "sunroof" refers to a roof that has an opening to let sunlight in.
Think of the 'sun' shining through an opening in the 'roof' of a car — that's what a sunroof does.