suffix, ichidan verb
manage to do; succeed in doing; see through; finish doing
Attaches to the -masu stem of a verb to express successfully completing the action, often with a sense of effort or perseverance. It is usually written in kana.
最後まで走りおおせた。
I managed to run all the way to the end.
彼は難しい仕事をやりおおせた。
He succeeded in doing the difficult task.
この本を一晩で読みおおせるのは大変だ。
It's tough to finish reading this book in one night.