Fun fact, "Barbarian" is a Greek word as a label for non-Greeks. To the Greeks, foreign languages just sounded like they were mumbling "bar-bar-bar", hence Barbarians = Non-Greeks.
Interesting. Though I knew Sanskrit (well in school), didn't know or remember that word - but still know Hindi well, and in Hindi, bad-bad (pronounced like bud-bud) means blabbing, as in:
Kya bad-bad kar rahe ho - What are you blabbing.
And to close the loop, in Hindi, the sounds r and d are closely related and sometimes substituted for one another - at least while talking.