True value to dip (5)
I believe the answer is:
souse
'dip' is the definition.
(synonyms)
'true value' is the wordplay.
'true' becomes 'so' (similar in meaning).
'value' becomes 'use' (I've seen this before).
'so'+'use'='SOUSE'
'to' is the link.
(Other definitions for souse that I've seen before include "Wash" , "Pickle - drunkard" , "Duck" , "thoroughly wet" , "Pickled meat" .)