The term nodachi (kanji: 野太刀) means "field sword" in English. It is written のだち in hiragana. It's pronounced roughly like "no dah chee".
Another term for the odachi (大太刀), a large tachi. For this term, 野, no, means field. This character cannot stand alone. The typical word for field is nohara, 野原, のはら.
野 is also pronounced ya, as in yakyu (野球, やきゅう), the Japanese word for baseball. An odachi set aside for field battles (yasen, 野戦, やせん) can be called a nodachi. This, at least, is the most widely accepted theory as to how the distinction between odachi and nodachi came about.