Last name Seyly (Seyly 
) , in the entire world, is a very rare family name. The cognomen Seyly is characteristic of Latin America and the Caribbean, particularly Honduras, where it is a rare surname, Nicaragua, where it is a very rare surname, and Venezuela, where it is an extremely rare surname. Not in comparison with a country's population, it is the most numerous in Latin America and the Caribbean, particularly Honduras, Mexico, and Nicaragua. Likewise, Seyly is the forename as well as the last name.