godan verb (-ru), transitive verb
scribble down; dash off; write quickly and roughly
Implies writing in a hurried, careless, or rough manner, often with a sense of urgency or lack of polish.
彼はメモを書きなぐった。
He scribbled down a memo.
アイデアを忘れないように、ノートに書きなぐった。
I dashed off my ideas in a notebook so I wouldn't forget them.