Does cannon shot flash? (10)
I believe the answer is:
nanosecond
'flash?' is the definition.
(both can mean a small period of time)
'does cannon shot' is the wordplay.
'shot' is an anagram indicator.
'does'+'cannon'='doescannon'
'doescannon' with letters rearranged gives 'NANOSECOND'.
(Other definitions for nanosecond that I've seen before include "Only a little flash" , "next to no time!" , "trice" , "A very short interval of time" , "Tiny duration" .)