Tiny dame, surprisingly explosive (8)
I believe the answer is:
dynamite
'explosive' is the definition.
(dynamite is a kind of explosive)
'tiny dame surprisingly' is the wordplay.
'surprisingly' indicates an anagram.
'tiny'+'dame'='tinydame'
'tinydame' is an anagram of 'DYNAMITE'.
(Other definitions for dynamite that I've seen before include "Fantastic" , "Nobel's invention" , "might one be blown away by it?" , "Nitroglycerine explosive" , "Explosive - amazing thing" .)