Mind you, in several programming languages objects can have instance-specific methods (Ruby and Python being notable examples). This alone makes object more than merely a sum of a predefined structure having data fields and (also predefined) schema having functions to operate on those fields.
Look at the matter this way: CouchDB, MongoDB, and ElasticSearch, all use the term "document" to describe hash containing data of JSON-compatible model. They already do so, and they are quite well known in the field. It only makes sense to follow their lead, so your potential users can recognize capabilities of your application easier.
