Thought that I made gin perhaps (8)
I believe the answer is:
imagined
'thought' is the definition.
('imagine' can be a synonym of 'think')
'i made gin perhaps' is the wordplay.
'perhaps' indicates anagramming the letters.
'made'+'gin'='madegin'
'madegin' anagrammed gives 'magined'.
'i'+'magined'='IMAGINED'
'that' acts as a link.
(Other definitions for imagined that I've seen before include "Not based on fact, dubious" , "Supposed" , "Conceived of" , "thought" , "Dreamt up" .)