Am quite accustomed to being entertained (6)
I believe the answer is:
'being entertained' is the definition.
'am quite accustomed' is the wordplay.
'quite accustomed' becomes 'used' (I've seen this in another clue. I am not sure about the 'quite' bit.).
'to' acts as a link.
Can you help me to learn more?
(Other definitions for amused that I've seen before include "Pleasantly occupied" , "Beguiled" , "Delighted" , "Made (someone) laugh" , "Mildly diverted or entertained" .)