obviously fake story; likely untrue post
Internet slang for a social media post or story that is almost certainly a lie, often used jokingly or to call out fabricated content.
Another obviously fake story is going around.
That post is clearly a made-up story, isn't it?
A blend of 嘘 (uso, 'lie') and 松 (matsu, 'pine tree'), originating from a Japanese internet meme where a user fabricated a story about a pine tree. The term spread as a label for obviously false online posts.