After a term has been requested and had some --or all-- of its translations published to Glossaries through the Approval Workflow (find more about here) it can still be edited.
This article describes how that is done.
Finding Term and Requesting to Edit
In order to find the term you need to Edit, select the T icon (Terminology) on left menu and click on the option "Search Terms" at the top. Then type your search term and criteria and hit the "Search" button.
The terms matching your search criteria will show up at the left hand side list, right below "Glossary Terms" (see image below):
When you select the exact term you want to edit from the list on your left, the detailed information of the term will be displayed at the right. Once you click the button "Actions" at the upper right side of your term, you will the the options to request a term Edit (see detail image below).
After you have placed a request for a term to be edited, it will go through the Approval Workflow until all the translations have been review, approved and published.
To understand more about the Bureau Works Approval Workflow, read this article.