ret·ro·grade / ˈretrəˌgrād/ • adj. directed or moving backward: a retrograde flow. ∎  reverting to an earlier and inferior condition: to go back on the progress that has been made would be a retrograde step. ∎  (of the order of something) reversed; inverse: the retrograde form of these inscriptions. ∎  (of amnesia) involving the period immediately preceding the causal event. ∎  Geol. (of a metamorphic change) resulting from a decrease in temperature or pressure. ∎  Astron. & Astrol. (of the apparent motion of a planet) in a reverse direction from normal (from east to west), resulting from the relative orbital progress of the earth and the planet. The opposite of prograde. ∎  Astron. (of the orbit or rotation of a planet or planetary satellite) in a reverse direction from that normal in the solar system.• n. rare a degenerate person.• v. [intr.] 1. archaic go back in position or time: our history must retrograde for the space of a few pages. ∎  revert to an earlier and usually inferior condition: people cannot habitually trample on law and justice without retrograding toward barbarism.2. Astron. show retrogradation: all the planets will at some time appear to retrograde.DERIVATIVES: ret·ro·grade·ly adv. ( rare ).

retrograde Used in a planetary context to denote a body moving in the opposite sense to that of most solar-system bodies, i.e. clockwise rather than anticlockwise. The classic example is the retrograde rotation of Venus. Triton is in retrograde orbit around Neptune. At least four of the outer satellites of Jupiter, and one of Saturn, are also in retrograde orbits.

retrograde (astron., of planets) moving apparently in a direction contrary to the order of the signs XIV; tending or inclined to go backwards XVI. — L. retrōgradus, f. RETRO- + gradus step.
So vb. XVI. — L. retrōgradī, later retrōgradāre. retrogradation XVI. — late L. Hence retrogression XVII.

retrograde (ret-roh-grayd) adj. going backwards, or moving in the opposite direction to the normal. See also (retrograde) amnesia, (retrograde) pyelography.