Taxing a couple in middle of rural America (7)
I believe the answer is:
arduous
'taxing' is the definition.
(thesaurus)
'a couple in middle of rural america' is the wordplay.
'a couple' becomes 'duo' ('duo' can be a synonym of 'couple'**).
'in' means one lot of letters goes inside another.
'middle of' indicates the central letters.
'rural' becomes 'farm' ('farm' can be similar in meaning to 'rural').
'america' becomes 'us' (abbreviation for the United States).
The central letters of 'farm' are 'ar'.
'ar'+'us'='arus'
'duo' going inside 'arus' is 'ARDUOUS'.
(Other definitions for arduous that I've seen before include "Toilsome" , "Steep - hard" , "Gruelling, strenuous" , "Steep; laborious" , "Difficult, tiring" .)