The term nihonto (kanji: 日本刀) means "Japanese sword" in English. It is written にほんとう in hiragana. It may also be rendered in English as nihontō , nihontou , nihon-to , nihon-tō or nihon-tou. It's pronounced roughly like "knee-hone-toe".
The kanji 日本 means Japan and 刀, sword. (By itself, the latter is read as katanaKATANA 刀 "sword" learn more....) 日本, in addition to Nihon, is also pronounced Nippon, and to this day neither pronunciation has been declared the official one. Nippon having the stronger sound, it is used, for example, in the Olympics or in patriotic speeches. The Empire of Japan was called Dai Nippon Teikoku (大日本帝国); it was never Dai Nihon (dai means “great”).
Note that nihonto is a catch-all term for Japanese swords. It can also be used to refer to a particular sword, but only so as to distinguish it from non-Japanese swords.