Clobber in ring? One packing punches around top of ribs (5,6)
I believe the answer is:
boxer shorts
'clobber in ring?' is the definition.
(shorts worn in a boxing ring)
'one packing punches around top of ribs' is the wordplay.
'one packing' becomes 'boxer' (someone boxing things up).
'punches' becomes 'shots' (shot can mean a punch).
'around' means one lot of letters goes inside another.
'top of ribs' becomes 'r' (I am not sure about this - if you are sure you should believe this answer much more).
'shots' placed around 'r' is 'shorts'.
'boxer'+'shorts'='BOXER SHORTS'
Can you help me to learn more?
(Other definitions for boxer shorts that I've seen before include "Men's underwear" , "Male underwear" , "Men's underpants" , "pants" .)