noun, noun or participle which takes 'suru', intransitive verb
reminiscent smile; laughing at a memory
The act of smiling or laughing to oneself when recalling a pleasant or amusing past event. Often used as a noun or with する.
彼はふと思い出し笑いをした。
He suddenly smiled to himself at a memory.
電車の中で思い出し笑いしてしまっ
I ended up laughing to myself on the train as I recalled something.