What does googoogaga mean?

"Googoogaga" doesn't have a specific meaning in any language or context. It's most likely a nonsensical sound, perhaps a:

* Baby babble: Babies often make sounds like this as they're learning to speak.

* Imitation: Someone might make this sound to imitate a baby or to be silly.

* Sound effect: It could be used in a cartoon or movie as a funny or nonsensical sound.

Without more context, it's impossible to determine a specific meaning.