Thought me old-fashioned about it (9)
I believe the answer is:
meditated
'thought' is the definition.
(meditating is a kind of thinking)
'me old-fashioned about it' is the wordplay.
'old fashioned' becomes 'dated' (I've seen this before).
'about' indicates putting letters inside.
'dated' placed around 'it' is 'ditated'.
'me'+'ditated'='MEDITATED'
(Other definitions for meditated that I've seen before include "pondered" , "thought" , "Engaged in religious contemplation" , "Engaged in spiritual contemplation" .)