The term kaigunto (kanji: 海軍刀) means "Navy military sword" in English. It is written かいぐんとう in hiragana. It may also be rendered in English as kaiguntou , kaiguntō , kai-gunto , kai-guntou , kai-guntō , kai gunto , kai guntou or kai guntō. It's pronounced roughly like "kigh goon toe".
The type of gunto (military sword) that was used by the navy (kaigun), specifically by the naval officers and especially during World War II. The 海 kanji, in the Japanese pronunciation, is umi and means sea. In the proper names of seas, it takes on the form of the suffix pronounced kai. The Sea of Japan, thus, is Nihonkai (日本海, にほんかい).