This is the 8889th most frequent Japanese word.
正一
"正一" can mean "first or foremost in righteousness" or serve as a male given name depending on context.
Here, 正一 is used as a proper noun, specifically as a name.
私の友人の名前は正一です。
My friend's name is Shoichi.
正一 is combined with 秒 (second) to emphasize precision, translating to 'exactly one second' or 'every single second'.
彼は正一秒を争う忙しい仕事をしています。
He is engaged in a job where every single second counts.
正一 is used with 階 (floor) to indicate an exact amount, meaning 'exactly one floor' in this context.