suffix
Attaches to a noun to mean the end of that thing, often with a nuance of finality or closing up. Common in compounds like 店じまい (closing a shop for the day or for good).
See also: 店じまい
今日はもう店じまいにしよう。
Let's close up the shop for today.
長い一日の仕事じまいに、一杯やるのが楽しみだ。
I look forward to having a drink at the end of a long day's work.
suffix
ending up not doing; without having a chance to
Attaches to the 〜ず negative form of a verb to express regret or disappointment that something ended without the intended action taking place. Often implies 'before I could even...'.
結局、彼に何も言わずじまいだった。
In the end, I ended up not saying anything to him.
買おうと思っていた本を買わずじまいで、売り切れてしまった。
I ended up not buying the book I wanted to, and it sold out.