Congenital absence of phalanx, digit, hand, or foot

Polydactyly or polydactylism (from Greek πολύς (polys) 'many', and δάκτυλος (daktylos) 'finger'), also known as hyperdactyly, is an anomaly in humans and animals resulting in supernumerary fingers and/or toes. Polydactyly is the opposite of oligodactyly (fewer fingers or toes). [Source: Wikipedia ]