Trashiness is the noun for being trashy — the quality of being very bad, cheap, or of low value. You use it when you want to name that quality as a thing, not just describe something: 'the trashiness of the film', 'a certain trashiness'. It covers two connected ideas. One is simply bad quality: cheap material, careless work, something that falls apart. The other is more about taste — vulgar, cheap-looking, trying too hard, the kind of thing people enjoy but feel a bit embarrassed about. Here is the part worth knowing: trashiness is often said with a smile. People talk about the trashiness of a TV show they watch every week and love. 'I watch it for the trashiness' means 'I know it's bad and that's the fun'. So it is an insult, but a soft and sometimes affectionate one. It is not a common word; 'trashy' is far more common. You will mostly meet trashiness in reviews and in writing about films, books, and TV, where someone wants a noun to hang a sentence on.

低俗；粗劣；廉價感（形容作品品質差、格調低）。中文常用「很芭樂」「很俗」「很爛」來講這種感覺，但那些是形容詞；trashiness 是把那個特質當成一個名詞在講