Hydroaeroplane is a term that refers to a seaplane or an aircraft designed for taking off and landing on water. However, there are other words that can be used as synonyms for hydroaeroplane depending on the region and context. In North America, the term "floatplane" is often used to describe this type of aircraft. In Europe, the term "amphibian" is used, which refers not only to seaplanes but also to planes that can operate both on land and water. Other synonyms for hydroaeroplane include seaplane, waterplane, and flying boat. These terms may be used interchangeably depending on the specific attributes of the aircraft design and intended use.