Issues summit discuss regularly (6)
I believe the answer is:
topics
'issues' is the definition.
('topic' can be a synonym of 'issue')
'summit discuss regularly' is the wordplay.
'summit' becomes 'top' ('top' can be a synonym of 'summit').
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternate letters of 'discuss' are 'ics'.
'top'+'ics'='TOPICS'
(Other definitions for topics that I've seen before include "Subject matter of conversations" , "'Matters dealt with, in conversation say (6)'" , "Subjects about optics" , "Subject matters" , "Subjects to talk about" .)