Here are some possibilities:
* "Depo" could be a shortened form of "depot," which refers to a place where goods are stored or transported. For example, a bus depot or a train depot.
* "Depo" could be a shortened form of "deposit," which means to put something in a place for safekeeping. For example, a bank deposit or a security deposit.
* "Depo" could be a misspelling of "depot" or "deposit."
Without more context, it's difficult to say for sure what "depo" means. If you can provide more information about where you encountered this prefix, I might be able to help you understand its intended meaning.