Article covering origins of import tariff and tax (5)
I believe the answer is:
tithe
'tax' is the definition.
(thesaurus)
'article covering origins of import tariff' is the wordplay.
'article' becomes 'the' (the 'definite article' part of speech**).
'covering' is an insertion indicator.
'origins of' indicates taking the first letters.
The initial letters of 'import tariff' is 'it'.
'the' placed around 'it' is 'TITHE'.
'and' is the link.
(Other definitions for tithe that I've seen before include "church funding" , "property tax" , "Tenth part paid to a church" , "Ancient tax" , "Levy of one tenth of something" .)