adj., n., & v.
adj. 1 directed backwards; retreating. 2 reverting esp. to an inferior state; declining. 3 inverse, reversed (in retrograde order). 4 Astron. in or showing retrogradation.
n. a degenerate person.
v.intr. 1 move backwards; recede, retire. 2 decline, revert. 3 Astron. show retrogradation. retrogradely adv.
[ ME f. L retrogradus (as RETRO-, gradus step, gradi walk) ]