随口一说英语

Speaks thoughtlessly asks

off the top of one's head 临时一想，随口一说 1.She recited the poem off the top of her head. 她即兴背诵了诗歌.2.I answered his question off the top of my head. 我没有认真考虑就回答了他的问题。

blurt out whatever comes into one's head或者：speak without thinking

Never mind 随便说说Incidently， by the way 顺便说一下

楼上各位都不对,by the way 是"顺便说一下"的意思,随便说一下应该是 say it casually.表示不是有意去说.