1.
inevitably; necessarily; as a natural consequence
Something that happens as a logical or unavoidable result of circumstances. Indicates that an outcome was bound to occur given the conditions.
必然的にそうなる。
It will inevitably turn out that way.
If the population increases, the demand for food will inevitably increase as well.
Usage
必然 means "inevitability" or "necessity" and 的に makes it an adverb. Used in logical arguments, analysis, and formal writing to describe outcomes that follow naturally from given conditions. More formal and analytical than 必ず (certainly, always).
The na-adjective form 必然的な is also common: 必然的な結果 (an inevitable result).