Dry area surrounded by sea in part of Europe (8)
I believe the answer is:
brittany
'part of europe' is the definition.
('Brittany' is part of 'europe')
'dry area surrounded by sea' is the wordplay.
'dry' becomes 'tt' (abbreviation for teetotal).
'area' becomes 'a' (maths abbreviation).
'surrounded by' is an insertion indicator.
'sea' becomes 'briny' ('briny' can be a synonym of 'sea'**).
'tt'+'a'='tta'
'tta' going within 'briny' is 'BRITTANY'.
'in' is the link.
(Other definitions for brittany that I've seen before include "French region where Bretons come from" , "Region of NW France" , "Part of France" , "Province of northwestern France" , "Tiny brat (anag) - region of France" .)