To finish or bring something to an end; to stop or close off an activity (used as a main/transitive verb).
会議をしまう前に、議事録を確認してください。
Before finishing the meeting, please check the minutes.
この仕事は今日中にしまわなければならない。
We must finish this work by today.
祭りをしまうのは深夜になるだろう。
They will probably finish/close the festival late at night.
To close down (a shop, business, etc.); to shut up/close (a place or operation).
うちの店は八時にしまいます。
Our shop closes at eight o'clock.
会社をしまって地方に帰った人もいる。
Some people closed their businesses and returned to the countryside.
今年はあの店もしまってしまったらしい。
It seems that that shop shut down this year.
To put away, store, or put back something in its proper place.
靴を下駄箱にしまってください。
Please put your shoes away in the shoe cupboard.
読んだ本は元の棚にしまっておいてください。
Please put the book you read back on its shelf.
使い終わった道具はちゃんとしまってから帰る。
Make sure to put away the tools properly after using them before you leave.
Auxiliary: attached after the -te form to indicate completion or that something has been done completely (often carries a sense of finality).
宿題を全部やってしまった。
I've finished all my homework.
うっかりスマホを電車に置き忘れてしまった。
I absentmindedly left my phone on the train.
この味、全部食べてしまいたいくらいおいしい。
This tastes so good I could eat it all up.
約束を忘れてしまったことを謝ります。
I apologize for having forgotten the appointment.
Auxiliary: attached after the -te form to indicate doing something accidentally or unintentionally; to end up doing something.
鍵を落として壊してしまった。
I dropped the key and accidentally broke it.
彼に本当のことを言ってしまったら、関係がぎくしゃくした。
When I told him the truth (without meaning to), our relationship became awkward.
ケーキをひっくり返してしまった。
I ended up flipping the cake over (accidentally).