Methinks there's no ink that contains a violet dye (5)
I believe the answer is:
meths
'contains a violet dye' is the definition.
I can't tell whether this defines the answer.
'methinks there's no ink' is the wordplay.
'there's no' is a deletion indicator.
'methinks' with 'ink' taken away is 'METHS'.
'that' is the link.
Can you help me to learn more?
(Other definitions for meths that I've seen before include "Methylated spirits (colloq.)" , "unsuitable alcohol" , "Violet-coloured alcohol" , "Fuel" , "Spirit" .)