Show shield off and get knocked down (10)
I believe the answer is:
demolished
'knocked down' is the definition.
(I've seen this before)
'show shield off' is the wordplay.
'show' becomes 'demo' (I've seen this in another clue).
'off' indicates anagramming the letters.
'shield' is an anagram of 'lished'.
'demo'+'lished'='DEMOLISHED'
'and get' is the link.
(Other definitions for demolished that I've seen before include "Knocked down" , "Razed to the ground" , "crushed" , "consumed voraciously" , "broke down" .)