The term 'Sort of Seabird' can be solved by two crossword solutions: TERN (4 letters) and AUK (3 letters). Terns are a group of seabirds that have long, pointed wings and a forked tail. They are found in many parts of the world, including North America, Europe, and Asia. Auks are a family of seabirds that are characterized by their short wings and webbed feet. They are found mainly in the Northern Hemisphere, particularly in the Arctic and subarctic regions.