Vocabulary What does 洗脳 (せんのう, sennou) mean? 洗脳 (せんのう, sennou) means brainwashing. Quick factsReadingせんのうRomajisennouPart of speechnoun, suru verb, transitive 洗脳せんのうsennoubrainwashing1noun · suru verb · transitive brainwashingKanji in this word洗wash脳brain