Step 1 : Introduction to the question "I saw the man ______ into the room, despite the "Do Not Disturb" sign hanging from the doorknob."
...In addition to meaning “to enter suddenly or forcibly,” irrupt can be used to describe the sudden arrival of a large population in an area. The largest human irruption? The annual period known as Chunyun, when Chinese people travel back to China to celebrate the Lunar New Year. This period accounts for nearly 3 billion trips each year.