土俵
どひょう · dohyou · JLPT N1 · noun
sphere
🤼 土 earth + 俵 straw bale: a sumo ring of packed earth edged with straw bales
The ring where sumo wrestlers compete was originally marked by rice-straw bales set on bare earth. 土俵 literally names that earth-and-straw boundary.
土 — pictograph of a mound of earth on the ground
土 is a pictograph showing a lump or mound of soil resting on the ground line. In oracle bone script it depicted an earthen heap, sometimes interpreted as an altar to the earth god. The meaning has remained stable: earth, soil, or ground.