Fear will collapse, getting security software (8)
I believe the answer is:
firewall
'security software' is the definition.
'fear will collapse' is the wordplay.
'collapse' indicates anagramming the letters.
'fear'+'will'='fearwill'
'fearwill' is an anagram of 'FIREWALL'.
'getting' acts as a link.
(Other definitions for firewall that I've seen before include "A protective system" , "Software protection for computer" , "network protection" , "Computer security system against online attack" .)