Arms manufacturer Sun might suspect (8)
I believe the answer is:
gunsmith
'arms manufacturer' is the definition.
'sun might suspect' is the wordplay.
'suspect' is an anagram indicator (a suspicious or unusual spelling).
'sun'+'might'='sunmight'
'sunmight' with letters rearranged gives 'GUNSMITH'.
(Other definitions for gunsmith that I've seen before include "Weapons maker" , "Thin mugs (anag.)" , "arms dealer" , "One makes or sells weapons" , "I can arm you" .)