Every single household and family knows
Used to indicate that something is known to everyone
Neutral
雷锋是一个家喻户晓的人物 | Léifēng shì yī gè jiāyùhùxiǎo de rénwù
Lei Feng is a household name
[Source]
爷爷是我们村家喻户晓的象棋好手，得了许多次冠军 | Yéyé shì wǒmen cūn jiāyùhùxiǎo de xiàngqí hǎoshǒu, dé le xǔduō cì guànjūn
My grandfather is a well-known Chinese chess player in our village, and he's won many championships
[Source]
Household name
家谕户晓 (jiā yù hù xiǎo)
This is an HSK chengyu
《汉书》(Hàn Shū), a work documenting the history of the Western Han dynasty (西汉, Xī Hàn, 206 BC - 8 AD). It was written by 班固 (Bān Gù), and is generally known in English as the "Book of Han" or the "History of the Former Han."
This chengyu is from a line in the work listed in the "Origin" section above