Lets hit out at national symbol (7)
I believe the answer is:
thistle
'national symbol' is the definition.
(symbol of Scotland)
'lets hit out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'lets'+'hit'='letshit'
'letshit' with letters rearranged gives 'THISTLE'.
'at' is the link.
(Other definitions for thistle that I've seen before include "Scots plant emblem" , "National emblem of Scotland" , "Prickly weed" , "Prickly plant (Carduus)" , "Scottish plant emblem" .)