Wild cat (tiger?) at edge of jungle — potential killer (9)
I believe the answer is:
cigarette
'potential killer' is the definition.
(smoking kills)
'wild cat tiger? at edge of jungle' is the wordplay.
'wild' is an anagram indicator.
'at' means one lot of letters go next to another.
'edge of' suggests the final letters (one of the letters on the edge of the word).
The last letter of 'jungle' is 'e'.
'cat'+'tiger'='cattiger'
'cattiger' anagrammed gives 'cigarett'.
'cigarett'+'e'='CIGARETTE'
(Other definitions for cigarette that I've seen before include "tobacco in consumable form" , "Fag, coffin nail" , "Fag, smoke" , "Something smoked" , "Tobacco wrapped in paper" .)