Nightclub entertainer beginning to shock tourist (8)
I believe the answer is:
stripper
'nightclub entertainer' is the definition.
(entertainer in a strip club)
'beginning to shock tourist' is the wordplay.
'beginning to' indicates taking the first letters.
'tourist' becomes 'tripper' (tripper is a kind of tourist).
The first letter of 'shock' is 's'.
's'+'tripper'='STRIPPER'
(Other definitions for stripper that I've seen before include "Erotic dancer" , "performer barely seen" , "Progressively barer performer" , "Waterproof boot" , "Paint remover" .)