Originally ferried across area to get exclusive (8)
I believe the answer is:
rarefied
'exclusive' is the definition.
(thesaurus)
'originally ferried across area' is the wordplay.
'originally' is an anagram indicator.
'across' is an insertion indicator.
'area' becomes 'a' (maths abbreviation).
'ferried' with letters rearranged gives 'rrefied'.
'rrefied' placed around 'a' is 'RAREFIED'.
'to get' acts as a link.
(Other definitions for rarefied that I've seen before include "Less dense or solid" , "'Of lower pressure than average, at high altitudes (8)'" , "Of air, thin as on high mountain" , "Less dense, like the upper air" , "Of air, thin as on high mountains" .)