angelfish is a compound of angel + fish, named for its wing-like fins resembling an angel's wings. Angel derives from Latin angelus, from Ancient Greek angelos ('messenger'). Morphologically, the word is transparent as a compound: its parts remain visible in the modern spelling, while the older history of those parts supplies the deeper ancestry. In modern use, the noun sense is "a brightly colored tropical fish with a flattened, disk-shaped body", which keeps the etymology connected to the word's present dictionary value rather than treating it as a merely historical label. The wider word family includes related English forms such as angel, angelic, showing how the same base continues to support neighboring English vocabulary. The principal historical forms in the chain include Ancient Greek angelos, Old English fisc, which anchor the explanation in named linguistic material.