The term RELATIVE HERON is composed of two crossword solutions, IBIS and HERON. An IBIS is a type of wading bird with a long, curved beak and a long neck, belonging to the family Threskiornithidae. The most common species of IBIS is the Sacred IBIS, which is native to Africa and parts of Asia. A HERON is a type of large wading bird with long legs and a long neck, belonging to the family Ardeidae. There are many species of herons, including the Great Blue HERON, which is found in North America. Therefore, the term RELATIVE HERON refers to the relationship between the IBIS and HERON, both of which are members of the same family of wading birds.