(sumo) the ring / a sandbag

(rare) a mole (burrowing insectivore) / (rare) an earthworm (worm (animal)) / (figuratively) an outstanding horse; an excellent horse; a famous horse (by metaphor from the meaning of the kanji)

Dominican Republic / Commonwealth of Dominica

(cooking) an earthenware pot used for cooking in Japanese cuisine

domain, scope, extent, range, territory / (computing) a domain / (business) a business's area of influence or operations / (taxonomy) a domain

(archaic) planet Saturn / Saturday

earth and sand

a surname

fun or entertaining for one person alone

something fun or entertaining for one person alone / (uncommon) Same as こま (koma) above