Vocabulary What does 一月 (いちがつ) mean? 一月 (いちがつ) means January (the first month of the year). Quick factsReadingいちがつLevel (estimated, JLPT framework)N5 一月いちがつN5 · estimated, JLPT frameworkJanuary (the first month of the year)Kanji in this word一one; the number 1月month; moon