word (ex. nubivagant), language (ex. Portuguese), topic (ex. love),
part of speech (ex. noun), origin (ex. origin: Latin), first letter (ex. A)
If it’s a stupid question, I’m stupid too, because I’m not a hundred percent sure myself. Technically, in the prefix form “meta-“, it means an abstract concept one level higher than a related concept. The internet has adapted it slightly to mean something closer to “self-aware” or “self-referential”, especially of art or literature.
Metadata (on a computer file) is data about data; the file is already data, but metadata is data like when the file was created and what format it’s in. A joke about jokes, a meeting about meetings, or a fanfiction about fanfiction would be meta.
Sometimes people use it in place of “ironic” or “off-topic”, but I don’t think that’s quite right. Um, I hope that helped you, because I think I’ve just confused myself more.