Themes or subjects (6)
I believe the answer is:
topics
I believe this is a double definition.
'themes' is the first definition.
(I know this)
'subjects' is the second definition.
(I know this)
(Other definitions for topics that I've seen before include "Subject matter of conversations" , "Subjects about optics" , "'Subjects, themes (6)'" , "Subject matters" , "'Matters dealt with, in conversation say (6)'" .)