go commandov.
To wear trousers without putting on underwear.
Example Citation:
"Comedian Dave Gorman is also firmly with the traditionalists. 'I'm never ever naked beneath my trousers. If God had wanted men to 'go commando' he wouldn't have invented polycotton with two per cent lycra! When my zip broke once I was glad to have boxers on.'"
—Alison George, "Is your man going commando?," Mail on Sunday, March 18. 2001
Earliest Citation:
Furthermore, colored briefs are 'sleazy' and going without underwear ('going commando,' as they say on campus) is simply gross."
—Jim Spencer, "Marking the Golden Anniversary of a Brief Success," Chicago Tribune, January 22, 1985
Notes:
I read several reports that claimed today's phrase came from Britain's Royal Marine Commandos who, one assumes, often go boxerless beneath their fatigues. I can't confirm that, but I do know that going commando hit the mainstream when it was used in a 1996 episode of the sitcom Friends. I managed to find a couple of dozen citations since 1996, but I found only one before that
