The Royal Spanish Academy (RAE) also offers the dictionary of the Royal Academy of Engineering (RAI). This dictionary works in a similar way to that of the RAE, with two additional filters in which you can search for a term or word by its exact definition or by an approximate definition. In addition, you can filter the definition you are looking for by the area of expertise such as aeronautics, chemistry, biology; there are up to 32 different categories.
You can consult this dictionary at: http://diccionario.raing.es/
The Interactive Terminology for Europe (IATE) is the EU’s terminology database that has been around since 1999, and it is in the process of being updated by EU institutions and bodies since the summer of 2004 to collect, divulge and manage the specific terminology of the European Union.
You can consult this dictionary at: https://iate.europa.eu/home
