gumshare 

When a person's intention is to share gum with only one other person but winds up giving gum to the entire class once they discover you have gum.

After giving away all of his gum, he realized he just had a gumshare with the class.

gumshare by Spiamaster October 23, 2009

Gumshark 

the act of farting on someone else. Pooting against someone else's body.

I will gumshark you if you don't behave!

Whenever I gumshark another person, they tend to find it gross, but hilarious at the same time.

Gumshark by Pcolalola May 14, 2010