Here are some possible interpretations:
* "Bass down": This could be a slang term related to music, referring to lowering the bass frequencies in a sound system.
* "Base down": This could be a shortened version of "base camp down," meaning the base camp has been established or is ready for use.
* "Basses down": This could be a plural version of "bass down," referring to multiple bass frequencies being lowered.
To understand the meaning accurately, please provide more context:
* Where did you encounter this phrase? (e.g., a song, a conversation, a book)
* What was the general topic?
With more information, I can give you a more precise answer.