expression
having nothing to do; at a loose end
A literary set phrase meaning to be idle or unoccupied, often with a reflective or poetic tone. Originates from the opening of the classic essay 徒然草 (Tsurezuregusa).
休日の午後、徒然なるままに散歩に出かけた。
On a holiday afternoon, with nothing particular to do, I went out for a walk.
徒然なるままに、日記を書くのも悪くない。
It's not bad to write a diary when you have time on your hands.