As a bit of a shock, trade union measure has satisfactory conclusion (5)
I believe the answer is:
tufty
'as a bit of a shock' is the definition.
(a bit of hair might be tufty - shock can mean hair)
'trade union measure has satisfactory conclusion' is the wordplay.
'trade union' becomes 'TU' (abbreviation for trade union).
'measure' becomes 'ft' (foot is a unit of measurement).
'has' means one lot of letters go next to another.
'conclusion' says to take the final letters.
The last letter of 'satisfactory' is 'y'.
'tu'+'ft'+'y'='TUFTY'
(Other definitions for tufty that I've seen before include "Covered with hair" , "Crested" , "With bunches of hair, say" , "in small clusters" .)