Fit worker getting drink after end of shift (7)
I believe the answer is:
tantrum
'fit' is the definition.
('tantrum' can be a synonym of 'fit')
'worker getting drink after end of shift' is the wordplay.
'worker' becomes 'ant' (worker is a type of ant).
'getting' is a charade indicator (letters next to each other).
'drink' becomes 'rum' (I've seen this before**).
'after' says to put letters next to each other.
'end of shift' becomes 't' (final letter of the word shift).
'ant' put next to 'rum' is 'antrum'.
'antrum' after 't' is 'TANTRUM'.
(Other definitions for tantrum that I've seen before include "fit of bad temper" , "Fit of childish temper" , "Pet, temper" , "Childish outbreak of temper" , "Burst of rage" .)