This repository hosts Portuguese WordNet data in textual format, this is an experimental branch of http://openwordnet-pt.org. It is linked to (but independent from) the Open English WordNet.
You can also get the data in JSON and RDF format.
See the Wiki for how the data was generated, how it compares to Princeton WordNet and what is the syntax of the text files. This data is validated and exported by the mill tool — see its repository for more information about validation, export formats, etc.