practical joke, prank

土性: of a person, earthen characteristics of personality, as based on the five classical Chinese elements of 木 (“wood”), 火 (“fire”), 土 (“earth”), 金 (“metal”), and 水 (“water”)

土星: (astronomy) Saturn, the planet

土製: to make something from soil or clay

門松: a traditional decoration consisting of pine boughs and other plant cuttings placed in pairs in front of a home for New Year

度合い, 度合: degree

土俵: sumo ring; a sandbag

"ditch river": river as dirty as a ditch; dirty river

The hiragana syllable どぅ (du). Its equivalent in katakana is ドゥ (du).

(onomatopoeia) sound of a heavy object falling into the water.