Think the notice about it seemed funny (6)
I believe the answer is:
amused
'seemed funny' is the definition.
Although both the answer and definition are past participle verbs, I don't understand how one could define the other.
'think the notice about it' is the wordplay.
'think' becomes 'muse' (to muse on something is to think about it).
'the notice' becomes 'ad' (both can mean an advertisement).
'about it' indicates putting letters inside (some letters go around or about others).
'muse' going into 'ad' is 'AMUSED'.
Can you help me to learn more?
(Other definitions for amused that I've seen before include "Beguiled" , "was entertaining" , "Medusa (anag)" , "Pleasantly occupied" , "Kept someone entertained" .)