Noun. Men's toilet. Usually public but sometimes also used to refer to a home toilet used by men. Origin probably "Gentlemen's toilet", abbreviated to "Men's toilet", further shortened to "Men's" or "Gents". After years of inaccurate sign writing on public toilets (internationally) the toilet can now be referred to as the "mens". Sometimes spotted as misspelt by learned old people who have not realised that words evolve. Note that the "Woman's toilet" can also be referred to as the "ladies" but not currently the "womans" (similar origin).
"Please stop the car, I need to visit the mens"
"Can I use your mens?"
"That was a dodgy curry, is there a mens I may use?"