「先月」 means last month, referring to the month immediately before the current one. This term is used to talk about events or activities that happened in the previous month. Useful for discussing recent past events.

今(いま)の月(つき)の一個(ひとつ)前(まえ)の月(つき)を意味(いみ)します。先月(せんげつ)あった出来事(できごと)や活動(かつどう)を話(はな)すときに使(つか)います。