Agency worker taking time signified outspoken attitude (11)
I believe the answer is:
temperament
'attitude' is the definition.
'agency worker taking time signified outspoken' is the wordplay.
'agency worker' becomes 'temp' (temporary worker sent from an agency).
'taking' is a charade indicator (letters next to each other).
'time' becomes 'era' (era is a kind of time).
'signified' becomes 'meant' ('mean' can be a synonym of 'signify').
'outspoken' indicates a 'sounds like' (homophone) clue.
'meant' sounds like 'ment'.
'temp'+'era'+'ment'='TEMPERAMENT'
(Other definitions for temperament that I've seen before include "Disposition; tuning adjustment" , "Piano tuning; character" , "Personality" , "Person's nature; adjustment in piano tuning" , "Frame of mind" .)