Origin; beginning; genesis — refers to the start or origin of something.
文明の原始を研究する学者が集まった。
Scholars who study the origins of civilization gathered.
事件の原始を詳しく調べる必要がある。
It's necessary to examine the origins of the incident in detail.
Primeval; primordial; primitive — describing something from the earliest times or in an undeveloped state.
原始時代の生活を想像するのは難しい。
It's hard to imagine life in the primordial/prehistoric age.
この道具は非常に原始的な作りだ。
This tool is made in a very primitive way.