Pure cold loathing overwhelming son (6)
I believe the answer is:
chaste
'pure' is the definition.
(chaste means abstaining from sex)
'cold loathing overwhelming son' is the wordplay.
'cold' becomes 'C' (eg on taps).
'loathing' becomes 'hate' (loathing is hatred).
'overwhelming' is an insertion indicator.
'son' becomes 's' (genealogical abbreviation for son).
'hate' going around 's' is 'haste'.
'c'+'haste'='CHASTE'
(Other definitions for chaste that I've seen before include "Cheats (anag.)" , "Pure and virginal" , "Pure - virtuous" , "Untouched ..." , "Pure and inviolate" .)