expression, i-adjective
Describes a subject, field, or skill that has many layers of complexity and cannot be easily mastered. Often used for arts, crafts, or intellectual pursuits. Compare with 奥深い, which is a single-word adjective with the same meaning.
See also: 奥深い (おくふかい)
茶道は本当に奥が深いですね。
The tea ceremony is truly profound, isn't it?
This game has simple rules, but it's deep.