The Context attribute of a term is what makes it unique in a localization project. So, if you want to add a term multiple times to a project, simply add it with a different Context value.
You can edit a term's Context value by going to the project page and accessing the localization project's Terms page.
We do not recommend adding comments in Context. POEditor has a dedicated comment system designed for communicating term-related things such as tone of voice or other translation aspects.