Somewhat apt unloaded firearm (1,6)
I believe the answer is:
a trifle
'somewhat' is the definition.
(I've seen this before)
'apt unloaded firearm' is the wordplay.
'unloaded' says to hollow out the word (remove centre letters) (the content of the word is unloaded).
'firearm' becomes 'rifle' (rifle is a kind of firearm).
'apt' with its centre removed is 'at'.
'at'+'rifle'='A TRIFLE'
(Other definitions for a trifle that I've seen before include "Slightly" , "somewhat" .)