Maybe I slew with a gun (5)
I believe the answer is:
lewis
'gun' is the definition.
(thesaurus)
'maybe i slew' is the wordplay.
'maybe' indicates an anagram.
'i'+'slew'='islew'
'islew' with letters rearranged gives 'LEWIS'.
'with a' is the link.
(Other definitions for lewis that I've seen before include "C. S. ---, --- Carroll, authors" , "gunman?" , "one often communicated with by Morse" , "Police sergeant" , "Inspector Morse's assistant" .)