retrograde vs move back

retrograde is an adjective but move back is not an adjective.

Word	Noun	Adjective	Verb	Adverb
retrograde	No	Yes	Yes	No
move back	No	No	Yes	No

As verbs, move back is a hypernym of retrograde; that is, move back is a word with a broader meaning than retrograde:

Other hypernyms of retrograde include draw back, pull away, pull back, recede, retire, retreat, withdraw.

retrograde (adjective)	move back (adjective)
of amnesia; affecting time immediately preceding trauma
moving from east to west on the celestial sphere; or--for planets--around the sun in a direction opposite to that of the Earth
going from better to worse
moving or directed or tending in a backward direction or contrary to a previous direction

retrograde (verb)	move back (verb)
get worse or fall back to a previous condition	pull back or move away or backward
go back over
move back
move in a direction contrary to the usual one
move backward in an orbit, of celestial bodies