Refrain from terror engulfing world (7)
I believe the answer is:
forbear
'refrain from' is the definition.
(thesaurus)
'terror engulfing world' is the wordplay.
'terror' becomes 'fear' (I've seen this before).
'engulfing' indicates putting letters inside.
'world' becomes 'orb' (I have seen 'The World' mean 'orb' so perhaps 'world' could also mean 'orb').
'fear' placed around 'orb' is 'FORBEAR'.
(Other definitions for forbear that I've seen before include "Refrain from doing something" , "Hold back" , "Be patient" , "Abstain" .)