Definitions of retrograde:

• verb:   go back over

  Example: "Retrograde arguments"

• verb:   move back

  Example: "The glacier retrogrades"

• verb:   move in a direction contrary to the usual one
• verb:   move backward in an orbit, of celestial bodies
• verb:   get worse; fall back to a previous or worse condition
• adjective:   going from better to worse
• adjective:   of amnesia; affecting time immediately preceding trauma
• 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:   moving or directed or tending in a backward direction or contrary to a previous direction