Authorise playing cards and prepare to start anew (5,3,5)
I believe the answer is:
clear the decks
'prepare to start anew' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'authorise playing cards' is the wordplay.
I cannot really see how this works, but
'authorise' could be 'clear' (synonyms) and 'clear' is found within the answer.
'cards' could be 'deck' (deck of cards) and 'deck' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'and' acts as a link.
Can you help me to learn more?
(Other definitions for clear the decks that I've seen before include "Get shipshape - prepare for action" , "tidy up after game of rummy" , "Prepare for action - these crackled (anag)" , "Remove obstacles to action" , "Tidy up after card-games" .)