to begin to write; to start writing
to write out (e.g. on a blackboard)
to extract (and write down); to write down (the important parts)
《computing》to export; to write (to file)
思いついたことを書き出した。
I wrote down what came to mind.
まず問題点を書き出してみよう。
Let's start by writing down the issues.
やることリストを紙に書き出すと頭が整理される。
Writing a to-do list on paper helps organize your thoughts.