One-man war 

1. A one-man war is when one person fights against an opponent consisting of several people by himself/herself.

2. It can also be used figuratively, to say a person is fighting against a matter that other people supports by himself/herself, at least with a lack of support for his/her opinion.

1. "He launched a one-man war against police."

2. "He launched a one-man war against graffiti."

One-man war by youngchimp December 5, 2012

One Man Thumb War 

Sexual act involving masturbating a girl, then having hand fall into the vagina without much effort. Man then begins to make thumb war motions inside girl. Works best on a loose girl.

I was totally getting it on with Darcy, and I put my hand down there, but it was a total one man thumb war not even a minute in.

One Man Thumb War by Kegan Godbey September 7, 2005

one man tug-of-war 

v.To masturbate aggressively.

Gareth eventually won the one man tug-of-war. It was hard going. But, in the end, he was covered in muck anyway

one man tug-of-war by Geoff Scotland July 24, 2008