There are more keys referring to BUMP; I have updated the topic.
All of them are in the “client” section, meaning on Transifex you can access them via: https://www.transifex.com/discourse/discourse-org/translate/#es_ES/core-client-yml
For the key js.topic.auto_bump.title, I think the best option is to keep “Auto-Bump” as is. In reality, the end user doesn’t see much of the “auto bump” part; they only see when the System revives the topic and they see the description:
BUMPED AUTOMATICALLY xx HOURS AGO
(see key: js.action_codes.autobumped)
In my community, I posted an announcement in the meta section explaining what “BUMPED” means so that curious users understand its purpose 
However, for the rest of the keys, end users don’t see them… only staff members would read them, and those people should already know what “bump” means in Discourse.
Question:
When you mention putting that, which key would it be?