Tense worker, perhaps having odd fit of temper (7)
I believe the answer is:
tantrum
'fit of temper' is the definition.
'tense worker perhaps having odd' is the wordplay.
'tense' becomes 't' (abbreviation used in many dictionaries).
'worker perhaps' becomes 'ant' (worker is a type of ant).
'having' is a charade indicator (letters next to each other).
'odd' becomes 'rum' (I've seen this before).
't'+'ant'+'rum'='TANTRUM'
(Other definitions for tantrum that I've seen before include "Child's outburst of bad temper" , "Spoilt brat's fit" , "Fit of childish temper" , "Childish angry outburst" , "petulant outburst" .)