Take flight, heading off for shelter (3)
I believe the answer is:
lee
'shelter' is the definition.
(thesaurus)
'take flight heading off' is the wordplay.
'take flight' becomes 'flee' ('flee' can be a synonym of 'take flight').
'heading off' means to remove the first letter.
'flee' with its first letter taken away is 'LEE'.
'for' acts as a link.
(Other definitions for lee that I've seen before include "Area sheltered from the wind" , "Cork river" , "Shelter" , "actor" , "The sheltered side - of Cork's river?" .)