1.AdverbTurned so that the back is now at the front; the wrong way around.
"I was in such a hurry that I put my underpants on back to front.; Of an order or cause of events, misunderstood or misinterpreted.; Of a perspective, reversed or inverted."
2.AdjectiveReversed, with the back now at the front.
"The classic VW Beetle is a back to front car, with the engine at the rear."