The term 'TERN RELATIVE' is a crossword solution that can be filled in with the word 'GULL'. Gulls are seabirds that belong to the family Laridae, which also includes terns. They are closely related and share many similarities, such as their long wings and webbed feet. Gulls are found in many parts of the world, including coastal areas, inland lakes, and even some urban areas. They are known for their scavenging habits and often feed on fish, insects, and other small animals.