noun, noun, used as a suffix
Abbreviation of 尽日 (じんじつ). Used as a suffix in month-end expressions like 月末 (げつまつ) or 三月尽 (さんがつじん). Rare as a standalone noun.
See also: 尽日 (じんじつ)
三月尽の日は三十一日です。
The last day of March is the 31st.
「尽」は月末を表す古い言い方で、今は「月末」のほう
尽 is an old way to say the end of the month; nowadays 月末 is more common.