Second kind of soldier, good and smart (5)
I believe the answer is:
sting
'smart' is the definition.
(both can mean to burn or hurt)
'second kind of soldier good' is the wordplay.
'second' becomes 's' (common abbreviation).
'kind of soldier' becomes 'tin' (I've seen this in another clue).
'good' becomes 'g' (abbreviation).
's'+'tin'+'g'='STING'
'and' acts as a link.
(Other definitions for sting that I've seen before include "Con: leader singer of Police" , "piece of deception" , "Undercover operation; wound" , "Bee/wasp wound" , "fraud" .)