Whine ... "Tin veil broken" (6)
I believe the answer is:
snivel
'whine' is the definition.
(synonyms)
'tin veil broken' is the wordplay.
'tin' becomes 'Sn' (Sn is the chemical symbol for tin).
'broken' indicates anagramming the letters.
'veil' with letters rearranged gives 'ivel'.
'sn'+'ivel'='SNIVEL'
(Other definitions for snivel that I've seen before include "Blub revoltingly" , "Complain tearfully" , "Complain self-pityingly" , "Whimper" , "Complain whiningly" .)