Definition of "Retrograde" :

verb: get worse or fall back to a previous condition

verb: go back over

"Retrograde arguments."

verb: move back

"The glacier retrogrades."

verb: move in a direction contrary to the usual one

verb: move backward in an orbit, of celestial bodies

adjective: of amnesia; affecting time immediately preceding trauma

adjective: moving or directed or tending in a backward direction or contrary to a previous direction

adjective: moving from east to west on the celestial sphere; or--for planets--around the sun in a direction opposite to that of the Earth

adjective: going from better to worse