A person who insecently steals or bums gum off of people because they are too lazy to go out and spend 35 cents to have their own.
"She's such a gum bummer. She got a piece of gum from me every day this week. What's up with that? She should go get her own."
by Lydia Suzanne May 17, 2007
1 more definition
Someone who always asks you for a piece of gum after seeing you pop a fresh piece.
I had a new pack today but because all these GumBummers I'm already OUT!!!
by JKELLO January 05, 2012