means The shimmering play of colors on a surface that shifts as you move or change your angle, like a soap bubble, oil slick, or peacock feather.

from From Latin 'iris,' meaning rainbow — itself borrowed from Greek 'iris,' the rainbow and the goddess who personified it, the messenger who slid down the arc between gods and mortals. The Greeks built the word from a root suggesting 'to bend' or 'curve.' English added '-escence,' a suffix denoting a process or state in bloom, to make 'iridescence' a 19th-century coinage — the act of being rainbow-like, caught in the moment of shimmering.