delete_entity_translations
Security covered
Overview
Deleting a language will remove all interface translations associated with it, but content in this language will be set to be language neutral and will not be deleted. The Delete Entity Translations module allow to delete entities and their translations for selected language before removing the language itself.
How to use
Go to admin/config/regional/delete-entity-translations, select the language with entity types you want to delete and run the process of deleting entities / translations. Here more detailed documentation with screens