Central jurídica is a portal that not only offers a dictionary and glossary of legal terms in Portuguese, but you can also find sample legal documents for each legal field, from sample contracts, to fines, sentences and even a compilation of Latin expressions most used in Portuguese law.
Follow the link for this resource: https://www.centraljuridica.com/dicionario/g/1/dicionario_juridico/dicionario_juridico.html
Joaquín Ramos offers a dictionary of legal terms provided by the department of Constitutional and Community Law of the University of Prague. This document comes as a free and open access PDF in which you will find the terms in alphabetical order.
Follow the link for this resource: https://www.instituto-camoes.pt/images/stories/tecnicas_comunicacao_em_portugues/portuges_institucional_e_comunitario/Glossario%20de%20termos%20juridico%20administrativos.pdf
Priberam is a dictionary of civil law terms in which you can find both terms and law vocabulary. Some of the definitions come with the etymology of the word, the original use and the evolution of the use of that term. You can also find informative articles on law.
Follow the link for this resource: https://dicionario.priberam.org/