Somewhat reactionary cabinet is bewildered by something in cyberspace (7)
I believe the answer is:
website
'something in cyberspace' is the definition.
'somewhat reactionary cabinet is bewildered' is the wordplay.
'reactionary' is a reversal indicator (reactions happen in the opposite direction).
'somewhat' indicates the answer is hidden within the clue.
'etisbew' is hidden within 'cabinet is bewildered'.
'etisbew' backwards is 'WEBSITE'.
'by' acts as a link.
(Other definitions for website that I've seen before include "A place on the Internet" , "Wikileaks maybe" , "Online location" , "On-line information pages" , "Internet address with prefix www" .)