Otagiri Dam^[1] (Japanese: 小田切ダム) (also sometimes read as Odagiri Dam^[2]) is a dam in the Nagano Prefecture, Japan, completed in 1954.^[3]

The name of the dam originates from the old village “Otagiri” (小田切)^{[4][circular reference]} (not "Odagiri"). Etymologically “Otagiri” consists of “O” and “tagiri”. “O” is a prefix of Japanese. “Tagiri” is the gerund of the verb “tagiru” (it means the motion of water like “boil”).^[5][6] In Nagano Prefecture there are many such place names like "Tagiri", “Ô-tagiri”,^{[7][circular reference]} "Naka-tagiri",^{[8][circular reference]} “Inu-tagiri”, “Fut-tagiri”, and “Ka-tagiri”.^{[9][circular reference][10][circular reference][11][circular reference][12]}