noun, adverb
Formal or literary term for the very beginning or origin of something. Often used in fixed expressions like 本初子午線 (prime meridian).
本初子午線は経度0度の線です。
The prime meridian is the line of 0 degrees longitude.
この儀式は本初の意味を忘れずに行われる。
This ceremony is performed without forgetting its original meaning.