noun
at the very beginning; first and foremost
A formal, literary expression used to emphasize the very start of something. Often found in written or rhetorical contexts rather than casual speech.
劈頭第一、この問題の重要性を強調したい。
First and foremost, I want to emphasize the importance of this issue.
A yojijukugo (four-character idiom) combining 劈頭 (opening, beginning) and 第一 (first, number one). The exact origin is uncertain, but it follows a common pattern of intensifying a concept by doubling similar-meaning elements.