User blog comment:Sarasue1/Millard High RP (Part 28)/@comment-1344907-20150313001755/@comment-1344907-20150322012713

((Don't remember where, but I heard somebody use that term for underwear. :o I guess it does sound kinda archaic, though.

According to here, it's British slang. Well...uh, let's just say he got that from his parents. ))