depths of the earth; underground depths
Refers to the deep interior of the earth, often with a sense of vastness or mystery. Used in both literal and figurative contexts.
Many unknown worlds still lie in the depths of the earth.
The novel is about an expedition into the depths of the earth.
subterranean humanoids; mole people
underground lake; subterranean lake
Compound of 地 (chi, 'earth') and 底 (tei, 'bottom'). The reading is on'yomi. The word is straightforward in formation and meaning.