Short sleep in between, a priority (3)
I believe the answer is:
nap
'short sleep' is the definition.
(a nap is a short sleep; 'short' suggests an abbreviation)
'in between a priority' is the wordplay.
'in' indicates a hidden word.
'NAP' is hidden within 'between a priority'.
(Other definitions for nap that I've seen before include "Little sleep" , "Quick sleep; raised pile" , "A fuzzy surface texture" , "A short sleep or snooze" , "Raised surface of a fabric and short sleep" .)