Sword charge? That is right (6)
I believe the answer is:
rapier
'sword' is the definition.
(sword used in fencing)
'charge? that is right' is the wordplay.
'charge?' becomes 'rap' (both can mean blame or responsibility).
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'right' becomes 'r' (abbreviation).
'rap'+'ie'+'r'='RAPIER'
(Other definitions for rapier that I've seen before include "Fine-bladed sword" , "Narrow sword with two-edged blade" , "Thin sharp sword" , "Thrusting weapon" , "Sword for thrusting" .)