Slang Definition: What Does 'Boo' Mean?

Boo (slang) – A term of endearment for a romantic partner (boyfriend, girlfriend, spouse) or close intimate friend. Equivalent to "babe," "bae," "sweetheart," or "honey."

Usage examples:

• "Hey boo, how was your day?"
• "My boo and I are celebrating our anniversary."

Origin: Likely from French beau (beautiful, admirer) via African-American Vernacular English (AAVE), popularized in 1990s hip-hop/R&B. Not to be confused with the exclamation "boo!" (expressing disapproval or scare).