Expert I snapped outside hotel bar (8)
I believe the answer is:
prohibit
'bar' is the definition.
(I know that bar is a more specific form of the action prohibit)
'expert i snapped outside hotel' is the wordplay.
'expert' becomes 'pro' (short for professional).
'snapped' becomes 'bit' (I've seen this in other clues).
'outside' indicates putting letters inside (some letters go outside others).
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'pro'+'i'+'bit'='proibit'
'proibit' enclosing 'h' is 'PROHIBIT'.
(Other definitions for prohibit that I've seen before include "Formally forbid" , "Forbid, ban" , "Bar" , "Disallow" , "Stop" .)