Douglas Harper's Etymology Dictionary
Pennsylvania Dutch ornamental bird design, from German Distelfink "goldfinch," literally "thistle-finch," from Old High German distilvinko, from distil "thistle" (see thistle) + Old High German finco "finch," from PIE *(s)ping- "sparrow, finch" (see finch). The bird so called because it feeds on thistle seeds. Compare Old French chardonel "goldfinch," from chardon "thistle."
Wiktionary
n. A stylized goldfinch in Pennsylvania Dutch folk art, representing happiness and good fortune.
Wikipedia
A distelfink is a stylized goldfinch, probably based on the European variety It frequently appears in Pennsylvania Dutch folk art. It represents happiness and good fortune and the Pennsylvania German people, and is a common theme in hex signs and in fraktur. The word distelfink (literally 'thistle-finch') is the German name for the European goldfinch.
Usage examples of "distelfink".
Blake had seen his mother spend hours inscribing the distelfink, the luck bird, by hand on the cookies she gave to acquaintances, but he had never known her to use these other hexes before.