Launch hotel address online (4)
I believe the answer is:
hurl
'launch' is the definition.
(I've seen this before)
'hotel address online' is the wordplay.
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'address online' becomes 'url' ( Uniform Resource Locator, as in a website address).
'h'+'url'='HURL'
(Other definitions for hurl that I've seen before include "Play with a sliotar" , "Fling" , "Throw forcibly" , "Throw violently" , "Throw forcefully" .)