Phrase that describes article found in Yorkshire's last mine (7)
I believe the answer is:
epithet
'phrase' is the definition.
(an epithet is a descriptive phrase)
'article found in yorkshire's last mine' is the wordplay.
'article' becomes 'the' (the definite article in English).
'found in' is an insertion indicator.
'last' suggests the final letters.
'mine' becomes 'pit' (down the pit).
The last letter of 'yorkshire' is 'e'.
'e'+'pit'='epit'
'the' going inside 'epit' is 'EPITHET'.
'that describes' acts as a link.
(Other definitions for epithet that I've seen before include "The 23: an -- for Richard I" , "title" , "Sobriquet" , "Descriptive term used to express a real quality" , "Adjective expressing some quality of a person" .)