(anatomy) either the spine, or the middle groove of the back along the spine / (clothing) the middle seam of the back

下奴: a servant, a maid; oneself (humble) / 家奴: a male servant; a tenant farmer; a peasant; the peasantry / 才: talent, quick-wittedness; one's characteristics or peculiarities

邪魔: to impede, to obstruct; to be a bother, obstacle, nuisance, hindrance

(of a heart) to pound