Charge second associate
I believe the answer is:
sally
'charge' is the definition.
(both can mean a military attack)
'second associate' is the wordplay.
'second' becomes 's' (common abbreviation).
'associate' becomes 'ally' (ally is a kind of associate).
's'+'ally'='SALLY'
(Other definitions for sally that I've seen before include "Retort - Gracie Fields song" , "Sortie; quip" , "one in 3 the 12 30 [DROP the DEAD DONKEY]" , "Charge" , "- - Lunn, flat cake" .)