Skilled in metrical patterns? (6)
I believe the answer is:
versed
'skilled' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for versed that I've seen before include "Proficient" , "Having knowledge, skilled - in poetry?" , "Trained" , "shows experience" , "Experienced or skilled in" .)