If you had children in the early part of the twentieth century, you probably clothed the babies in one-piece suits, a shirt and pants with snaps or buttons around the garments’ middles to allow easy access to diapers. You probably called it a “union suit” if it had long pants (maybe with feet), or a “pantywaist” if it had shorts.

Fast-forward a hundred years, and hardly anyone uses “union suit” or “pantywaist” to describe clothes. But “pantywaist” has endured, sometimes below the radar, as a mild slur, meaning someone who is weak; a sissy. It is almost universally applied to men.

That insulting definition of “pantywaist” (sometimes hyphenated as “panty-waist,” sometimes rendered as “panty waist”) first appeared in the 1930s, according to the Oxford English Dictionary, about twenty years after the first mention of the garment itself. It’s not a common usage, and, as might be expected for something considered derogatory, it shows up mainly in letters to the editor, editorials, and, now, blogs.

David Carr used it on the Media Decoder blog at The New York Times in a discussion of a new book about the Murdoch takeover of The Wall Street Journal: “Again and again, the new owners of The Journal see the newspaper’s critics as left-leaning pantywaists and ‘Columbia Journalism School’ types,” he wrote. (“I chose the word because I was trying to ape the kind of critiques that I read,” he said later.)

“Pantywaist” has a tinge of Victorian archaism about it, since not many remember its origin. And it has a tinge of Britishism about it too: One British columnist started calling President Obama “President Pantywaist” last April, and while the nickname hasn’t exactly zoomed to the top of the charts in the U.S., it has been used a number of times. Most slang of that time has joined the Carolina parakeet in extinction (Quick! What’s a “flivver”?), but “pantywaist” has survived, along with “hoosegow,” “gin mill,” and “golddigger.”

Regardless, it is an insult, so should be used with care.

That one-piece garment for babies, in the meantime, has become better-known as a “onesie.” But “Onesies” is actually a trademarked name; not all one-piece baby suits are “Onesies.” A true “Onesies” is more like a T-shirt that snaps at the crotch than a “pantywaist.” If it has legs, it’s probably a romper, or just a one-piece baby suit.

Merrill Perlman managed copy desks across the newsroom at The New York Times, where she worked for 25 years.