noun, noun which may take the genitive case particle 'no'
Describes something that exists or occurs without human intervention, or a quality that is inherent and unforced. Often used as a no-adjective.
This park retains scenery that is completely natural.
naturally; spontaneously; of its own accord
Used adverbially to describe something happening without external force or artificial effort, often with に or as an adverbial noun.
彼の笑顔には天然自然の優しさがある。
His smile has an innate gentleness.
The problem resolved itself naturally.
Children learn language spontaneously.
A yojijukugo combining 天然 (natural, innate) and 自然 (nature, spontaneous), reinforcing the idea of something being completely natural and unforced.