Briefly look good with weapon (6)
I believe the answer is:
glance
'briefly look' is the definition.
(to glance at something is to briefly look at it)
'good with weapon' is the wordplay.
'good' becomes 'g' (abbreviation).
'with' means one lot of letters go next to another.
'weapon' becomes 'lance' (lance is a kind of weapon).
'g'+'lance'='GLANCE'
(Other definitions for glance that I've seen before include "Glimpse" , "Swift look" , "Stroke - gander" , "Momentary look" , "A dart of the eye" .)