1Last month (the month before the current one); used as a noun or adverb in conversation.
先月、京都に旅行に行きました。
I traveled to Kyoto last month.
先月の売上は予想より良かった。
Last month's sales were better than expected.
先月からそのクラスを取っています。
I've been taking that class since last month.
先月は雨の日が多かった。
There were many rainy days last month.