Signature sound of 91-Across

BEEPBEEP

Think of the playful noise a small, round robot from a beloved sci-fi franchise makes when it moves or communicates.

This clue refers to the iconic "beep beep" sound made by the Road Runner in Looney Tunes cartoons, where 91-Across is likely "ROADRUNNER." The answer mimics the character’s signature noise, written as "BEEPBEEP" to match how it’s often spelled out for humor or clarity. It’s a playful nod to the cartoon’s sound effect, assuming the solver recognizes the reference.