Whoa! Hurricane engulfs Hawaiian island (4)
I believe the answer is:
oahu
'hawaiian island' is the definition.
(I've seen this before)
'whoa hurricane engulfs' is the wordplay.
'engulfs' indicates the answer is hidden within the clue.
'OAHU' is hidden in the letters of 'whoa hurricane'.
(Other definitions for oahu that I've seen before include "Chief island of Hawaii" , "Pacific island" , "Hawaiian island" , "popular Pacific location" , "Honolulu's island" .)