Given the paucity of electric kettles in the USA, I wonder how that term became so widespread.
Ironically in Europe where the IEC cables were familiar from kettles, they've largely been superceded by cables hardwired into a base pad onto which the kettle is set.
British English, most likely.
"Kettle lead" (Which is notched to indicate it can take a higher temperature and most of cables aren't that, they will be the c13 type), and their face lights up and a cable will be handed to me.
Just one of those things that's wrong, but it's not worth being pedantic over it, imo.