Raise tax within European sheltered zone (7)
I believe the answer is:
elevate
'raise' is the definition.
(synonyms)
'tax within european sheltered zone' is the wordplay.
'tax' becomes 'VAT' (British sales tax).
'within' means one lot of letters goes inside another.
'european' becomes 'E' (abbreviation e.g. EU).
'sheltered zone' becomes 'lee' (the side sheltered from wind).
'e'+'lee'='elee'
'vat' inserted inside 'elee' is 'ELEVATE'.
(Other definitions for elevate that I've seen before include "To raise in level" , "Raise to a higher position" , "Lift to higher place or position" , "Hoist" , "Raise or lift" .)