Listening to Geoffrey Nunberg’s “Fresh Air” commentary about not one-off Britishisms, I was struck by this: ” … when [the British] do send us an occasional blockbuster like Harry Potter, they’re considerate enough to Americanize ‘dustbin’ to ‘trash can’ and ‘pinny’ to ‘apron.'”
The reason I was struck is that, about fifteen years ago, shortly after we moved to a town in suburban Philadelphia, my older daughter, Elizabeth Yagoda, started to play soccer. When her team practiced, the girls on one side would put loose mesh jerseys–all of the same color–over their shirts. These were referred to as pinnies. Or at least that’s what I thought they were referred to as; the other possibility was some Southern-derived pronunciation of pennies. I had never heard the term before.
The mystery has persisted, till Nunberg’s comment inspired me to investigate. The OED’s definition of pinny is “A pinafore; an apron, esp. one with a bib.” The dictionary cites a 1939 Angela Thirkell novel: “If we had known mummie was coming, we’d have had our clean pinny on.”
Current British usage uniformly favors the apron meaning, as in this 2010 quote from The People about the Beckham family: “I can reveal Posh, 36, will be putting her pinny on to cook for the couple’s parents including Dave’s dad Ted, who has previously been shunned from the family’s festivities.” That meaning has not penetrated the U.S.
And what about the athletic usage? Wikipedia is of some help:
In modern times, the term “pinny” or “pinnie” has taken another meaning in sports wear, namely a double-sided short apron, often made of mesh, used to differentiate teams. This usage is chiefly British, with some usage in Canada and the United States. This type of pinny is also known as a scrimmage vest.[citation needed]
Citation needed indeed. I haven’t been able to find any British use–and would appreciate any reader input–but pinny appears to have been used to denote “scrimmage jersey” in the U.S. by the early 1950s. Renata Adler (born: 1938) writes in her 1976 novel, Speedboat, “It is all gone, after childhood knowledge of myths, constellations, baseball scores, dinosaurs, and idioms of the tennis court and athletic field. There are outcroppings of the old vocabularies still. Pinnies from field hockey. Heels down. Bad hop. Sorry. My fault. So sorry.”
And there is this in a 1951 publication called “Developing Democratic Human Relations” (the passage is apparently a list of guidelines for scholastic sports): “7. Short cuts to efficient organization for intramural programs (developed through the democratic process): a. Schedule for field and courts with the games schedule. b. Previous knowledge of pinny or shirt teams and direction of goal or basket…”
Today, the word is out there in America, but not completely familiar, as evidenced by way the singular is sometimes spelled pinny and sometimes pinnie, by the quotation marks in this 2012 New York Times blog post–“Children trade or alter clothing; they wear it in situations for which it wasn’t intended (a sports bra under a “pinnie”: perfect for lacrosse, less so in the classroom)”–and by the definition provided in this one, about a pickup soccer game:
“Sides of six to nine are assembled from players serendipitously wearing like-colored tops; noncoordinated participants, mostly men but some women, team up and wear borrowed practice pinnies (mesh vests).”
Almost precisely a year ago, ahead of the Harvard-Yale (American) football match–known in those parts as The Game–the Yale Daily News published this item:
In a clear demonstration that Harvard students measure their “superiority” by their university’s single-digit acceptance rate and their pinnies, a group of Harvard entrepreneurs have launched an “#OccupyYale” pinny — prominently displaying the school’s 6.2% admissions rate — for Cantabs to wear at The Game this weekend.

Pinny for your thoughts: typical Harvard arrogance