A sound made to express grief or sorrow, often in a mocking or exaggerated manner.

रोने की आवाज़

English Usage: "When she heard the sad song, she couldn't help but let out a little boo-hoo."

Hindi Usage: "जब उसने दुखभरा गाना सुना, तो वह थोड़ी बू-हू करने से खुद को नहीं रोक सकी।"