Gets ready to move yet again per returning new sack (7)
I believe the answer is:
repacks
'gets ready to move yet again' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'per returning new sack' is the wordplay.
'returning' says the letters should be written backwards.
'new' is an anagram indicator.
'per' in reverse letter order is 'rep'.
'sack' with letters rearranged gives 'acks'.
'rep'+'acks'='REPACKS'
Can you help me to learn more?
(Another definition for repacks that I've seen is " Once more fills".)