To Arrange, To Organize, To Sort
する verb, transitive verb
When you arrange something with reason you're arranging it. That's why this is to arrange.
せいりする
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
このデータを全て整理するには、かなり時間がかかると思います。
I think it will take quite some time to organize all this data.
ちょっと一回、話を整理させてもらっていいかな?
Can I take a moment to organize your story?
あの社員に、デスクを整理するよう言っておいて!
Tell that employee to tidy up their desk!