If you already have a glossary uploaded to Transifex and you need to download it, here are the steps you need to do to perform this action:
Access the Glossaries Overview section by clicking "Glossaries" in your organization dashboard's main menu.
Once the Glossaries Overview section is open, use the search bar to look for the glossary you want to download; after finding your glossary, go to the right side of your glossary element and click on the three dots symbol.
You will see a menu with multiple actions to perform in your glossary; click on the download glossary option in this menu, and a new screen will pop-out
In this screen, first, select the languages you want to download from your glossary; if you do not specify, it will download all languages by default. After selecting the languages you need, click on the "Download glossary" button, and that's all; your glossary will be downloaded in a CSV file.