to wear trousers with no underpants There isn't time to dress properly - we'll have to go commando.
in. [for a male] not to wear underpants. (see also go commando.) Geesh! It’s to cold out to freeball.
go commandoand go freeball(ing)
in. [for a male] to go about not wearing underpants. (The same as freeball.) Bobby is always going commando. Even when it’s cold.
See go commando
See also: freeball
To wear clothing without wearing undergarments, especially underpants.