Wind, destructive at the outset, coming in closer (7)
I believe the answer is:
meander
'wind' is the definition.
(synonyms)
'destructive at the outset coming in closer' is the wordplay.
'at the outset' suggests taking the first letters.
'coming in' indicates putting letters inside.
'closer' becomes 'meaner' (I am not sure about this - if you are sure you should believe this answer much more).
The first letter of 'destructive' is 'd'.
'd' put within 'meaner' is 'MEANDER'.
Can you help me to learn more?
(Other definitions for meander that I've seen before include "Wander without aim or direction" , "an Indo-European river" , "Renamed (anag)" , "Wander about, follow a winding course" , "Wander in leisurely way, like stream" .)