Often nurses left parcel out (5)
I believe the answer is:
allot
'parcel out' is the definition.
(synonyms)
'often nurses left' is the wordplay.
'often' becomes 'alot' (doing something often is doing it a lot).
'nurses' indicates putting letters inside (nurse can mean to hold onto or harbour).
'left' becomes 'l' (common abbreviation).
'alot' placed around 'l' is 'ALLOT'.
(Other definitions for allot that I've seen before include "Earmark" , "Give, apportion" , "grant" , "Apportion, share" , "Assign or distribute" .)