Definition of the word duck out

The expression "duck out" is a phrasal verb that means "to leave or depart quietly and quickly" in modern English. Its origins can be traced back to the 1840s, particularly in the theatre world. As the story goes, in earlier times, theatres had no designated areas for the exit of audience members. The only exits available were through the rear of the auditorium, as there were no aisles like in modern theatres. However, while performed, audiences might get restless or need to depart for any reason, causing chaos and disturbance in the theatre hall. To mitigate this problem, the actors on stage would initiate a scene or dialogue that would require their immediate exit, signalling the restless audience to also depart immediately without causing much fuss. The action of exiting the stage swiftly and quietly became known as "ducking out." The expression was picked up by the general population and became common parlance, meaning leaving quietly and unobtrusively, even in contemporary times.