Metal wrapped round large gavel (6)
I believe the answer is:
mallet
'metal wrapped round large gavel' is the definition.
'mallet' can be an answer for 'gavel' (I've seen this in another clue). I am unsure of the 'metal wrapped round large' bit.
'metal wrapped round large gavel' is the wordplay.
'metal' becomes 'Al' (chemical symbol for aluminium).
'wrapped' is an insertion indicator.
'round' indicates putting letters inside.
'large' becomes 'L' (eg in clothes sizes).
'gavel' becomes 'met' (I am not sure about this - if you are sure you should believe this answer much more).
'l' put within 'met' is 'mlet'.
'al' put into 'mlet' is 'MALLET'.
Can you help me to learn more?
(Other definitions for mallet that I've seen before include "An auctioneer's wooden hammer" , "Croquet stick" , "Type of hammer" , "Wooden-headed hammer" , "It's used in croquet and polo" .)