Prevent Richard speaking like a poet of old (6)
I believe the answer is:
bardic
'poet of old' is the definition.
'bardic' can be an answer for 'poet' (I've seen this before). I am not sure about the 'of old' bit.
'prevent richard speaking' is the wordplay.
'prevent' becomes 'bar' (bar can mean to prevent or disallow).
'richard speaking' becomes 'dic' (I can't explain this - if you can you should give a lot more credence to this answer).
'bar'+'dic'='BARDIC'
'like a' is the link.
Can you help me to learn more?
(Other definitions for bardic that I've seen before include "of a Welsh poet" , "Like an Eisteddfod poet" , "Like an ancient poet" , "Relating to Celtic poets" , "Poetic" .)