Turbulent state revolutionised dated model (6)
I believe the answer is:
tiswas
'turbulent state' is the definition.
(tiswas can mean a nervous state)
'revolutionised dated model' is the wordplay.
'revolutionised' shows that the letters should be reversed in order.
'dated' becomes 'saw' ('see' can be a synonym of 'date').
'model' becomes 'sit' (e.g. for a painting).
'saw'+'sit'='sawsit'
'sawsit' backwards is 'TISWAS'.
(Other definitions for tiswas that I've seen before include "commotion" , "state" .)