Straightforward, not elaborate (6)
I believe the answer is:
simple
This clue is a double definition.
'straightforward' is the first definition.
(thesaurus)
'not elaborate' is the second definition.
(I've seen this in another clue)
(Other definitions for simple that I've seen before include "Easily done" , "Uncomplicated; herb" , "A piece of cake" , "Easy; herb" , "Easy; plain" .)