Like something written in prison? (6)
I believe the answer is:
penned
'written in prison?' is the definition.
'penned' can be an answer for 'written' ('pen' can be a synonym of 'write'). I'm unsure of the 'in prison?' bit.
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for penned that I've seen before include "Wrote; enclosed" , "in Reading Gaol, perhaps" , "Wrote; confined" , "Put down" , "under house arrest?" .)