Opener for "O'Riley” or au rhum (4)

I believe the answer is:

baba

(Other definitions for baba that I've seen before include "infant" , "a little one" , "Rum fare" , "Rum-soaked sponge" , "Ali . . . . and the Forty Thieves" .)

I've seen this clue in The Wall Street Journal.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.