a man's pants, but only in the context of him being instructed to lose them. always had a slinky, horny vibe to it.
in my circle of pals in a small city in north america, from the 80s on, the word was really only heard in the phrase "drop those strides, cowboy..."
or perhaps that was only, um, in my geographical region? or my neighbourhood? or perhaps only my street. well, actually, maybe even only in my house. but nevertheless, there are enough men out there who are familiar with this usage that it deserves an entry in this distinguished forum.