Besides obvious フェークニュース, is there a natural Japanese expression to express the idea of fake?
On the same topic, how to say fake or shallow person? Is there an equivalent to plastic people in Japanese?
There is a single word that means "fake news".
Besides, if you want the adjective only, you can use:
For other phrases, I don't know much because I'm not familiar with colloquial English, but if I can put credit in Urban Dictionary's definitions (fake people, plastic people, read shallow person too but I didn't get what it is), I'd say:
for false rumor or fake news you can also say "dema" デマ