A contraction of "man" and "panties," the wordplay is meant to describe certain undergarments for males.
It's part of a special lexicon that has emerged, over the past decade, as a sort of shorthand for men's fashion. Men can also wear "mandals" (male sandals), "murses" (purses), "mantyhose" (pantyhose) and "mankinis" (swimsuit variants)—though not necessarily all at the same time.
At first, the neologisms were a kind of secret language among the fashion industry, etymologists say. Yet they're going mainstream. Now, editors of the prestigious Oxford English Dictionary are tracking them for possible inclusion.
The men's collection shows at New York Fashion Week, which kicks off Thursday, could give rise to more neologisms. Fashion editors often lack the words to describe wacky runway concoctions.