noun, noun or participle which takes 'suru'
laugh off; dismiss with a laugh
Used when someone treats a serious matter lightly by laughing, or when a joke or remark is so funny it metaphorically 'kills' the listener. Often used in the pattern 〜を笑殺する.
彼は私の提案を笑殺した。
He laughed off my proposal.
その冗談には笑殺された
I was killed by that joke (it was so funny).