1.
sleep-talking; talking in one's sleep
Words spoken unconsciously while sleeping.
子供の頃、よく寝言を言っていた。
When I was a child, I often talked in my sleep.
彼は寝言で何かつぶやいていた。
He was muttering something in his sleep.
2.
nonsense; absurd talk
Ridiculous statements that make no sense, as if spoken while dreaming. Often used dismissively.
寝言を言うな。そんなことできるわけがない。
Don't talk nonsense. There's no way that's possible.
WORD FORMATION:
寝 (sleep) + 言 (words)
COMMON EXPRESSIONS:
- 寝言を言う - to talk in one's sleep; to talk nonsense
- 寝言を言うな - don't talk nonsense (dismissive)
- 寝言は寝て言え - say your nonsense while sleeping (idiom meaning "stop talking nonsense")
RELATED 〜言 WORDS:
- たわ言 - nonsense, drivel
- 繰り言 - repetitive complaints
- 独り言 - talking to oneself
REGISTER:
Casual to neutral. The dismissive usage (sense 2) is informal.