First to take worker drink having fit of temper (7)
I believe the answer is:
tantrum
'fit of temper' is the definition.
(I've seen this in another clue)
'first to take worker drink' is the wordplay.
'first to' suggests taking the first letters.
'worker' becomes 'ant' (worker is a type of ant).
'drink' becomes 'rum' (rum is a kind of drink).
The initial letter of 'take' is 't'.
't'+'ant'+'rum'='TANTRUM'
'having' is the link.
(Other definitions for tantrum that I've seen before include "Childish fit of rage" , "Burst of rage" , "Child's outburst of bad temper" , "Spoilt brat's fit" , "Frenzy" .)