There's no official currency or unit of measurement called "dekadollar." It's likely a made-up term or a misspelling.

Here are some possible interpretations:

* A misspelling: Perhaps it's meant to be "decadollar," which would refer to ten dollars.

* A fictional currency: It could be a term used in a book, game, or other fictional context.

* A slang term: It might be a slang term used in a specific community or region, but it's not a widely recognized term.

To understand what "dekadollar" means, you'll need more context. Please provide additional information about where you encountered this term.