Harshness of truth coming after half of lies raised (8)
I believe the answer is:
severity
'harshness' is the definition.
(I know that harshness can be written as severity)
'truth coming after half of lies raised' is the wordplay.
'truth' becomes 'verity' (verity is a kind of truth).
'coming after' is a charade indicator (letters next to each other).
'half of' means to take half the letters.
'raised' is a reversal indicator (going up in a down clue).
'lies' with half the letters taken is 'es'.
'es' backwards is 'se'.
'verity' put after 'se' is 'SEVERITY'.
'of' is the link.
(Other definitions for severity that I've seen before include "Harshness, asperity" , "Intensity; harshness" , "Sternness" .)