What is mixte?

The Mixte is a type of "step-through" frame for bicycles. The step-through frame is the kind used in what were formerly called "womens", "girls", or "ladies" bikes. In contrast to the diamond frame that has a cross-bar running from a little below the handlebars to a little below the seat, a step-through frame instead has usually has bars running from just below the handle bars down to just above the pedals. The mixte frame variation instead has a pair of tubes running from the top of the head tube all the way back to the rear axle, connecting at the seat tube on the way.