Polydactyly or polydactylism (from Greek πολύς (polys), meaning 'many', and δάκτυλος (daktylos), meaning 'finger'), also known as hyperdactyly, is a congenital physical anomaly in humans and animals resulting in supernumerary fingers and/or toes. Polydactyly is the opposite of oligodactyly (fewer fingers or toes).