noun
delirious talk; ravings; nonsense
Refers to incoherent or irrational speech, often associated with fever, illness, or extreme agitation. Can also be used figuratively for absurd or nonsensical talk.
高熱でせんげんを言うようになった。
He started to talk deliriously because of the high fever.
彼の話はまるでせんげんだ。
His story is complete nonsense.