noun
last third of a month; 21st to the last day
Refers to the period from the 21st to the end of the month. Often used in scheduling, deadlines, and formal contexts. Compare with 上旬 (first 10 days) and 中旬 (middle 10 days).
会議は来月の下旬に予定されています。
The meeting is scheduled for the last third of next month.
レポートの締め切りは今月下旬です。
The deadline for the report is the end of this month.