Bishop nearly converted by cajoling talk (7)
I believe the answer is:
'cajoling talk' is the definition.
(I've seen this before)
'bishop nearly converted by' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'converted' indicates an anagram.
'by' says to put letters next to each other.
'nearly' anagrammed gives 'larney'.
(Other definitions for blarney that I've seen before include "Irish flattery" , "'Sweet talk, oul' guff (7)'" , "Soft soap" , "(Irish) talk" , "The Irish gift of the gab, and Cork Stone" .)