Emphasis on dialect (6)
I believe the answer is:
This clue is a double definition.
'emphasis' is the first definition.
'dialect' is the second definition.
'on' is the link.
(Other definitions for accent that I've seen before include "Mark over a vowel, perhaps" , "Emphasis on syllabus or word" , "Speech inflection" , "Regional speech characteristic" , "Emphasis on syllable or local pronunciation" .)