assistant or helper, as in: The Governor's aide will hold a press conference this afternoon
An aide is an assistant to someone who has an important job, especially in government or in the armed forces. a close aide to the Prime Minister. someone whose job is to help someone who has an important job, especially a politician (aide-de-camp)
(Advanced Intrusion Detection Environment) Public domain UNIX utility, similar to Tripwire, used to detect changes in important files