Over the course of the past few years, people have come to consolidate words in accordance to the green movement, and stricter school rules prohibiting homophobic language. So the words "gay" and "bum" have been combined into the ultimate beat down - "gum".
(inside the school hallway)
Kid: Look at that kid wearing the rainbow shoes, what a "gum"!
(teachers pass by)
Teacher: Yes those shoes do look like a niece piece of gum.