The word "初一" is formed by combining the character "初", which is a semantic-phonetic compound composed of the radical "衣" (clothing) and the component "刀" (knife), historically representing cutting cloth to initiate garment-making and thus conveying the meaning of "beginning" or "first", with the character "一", a pictographic numeral meaning "one", to collectively denote "first day" specifically in the context of the lunar calendar.