Groups of seven (7)
'groups of seven' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for septets that I've seen before include "Musicians" , "Groups of seven" .)
'groups of seven' is the definition.
(I've seen this before)
This is the entire clue.
(Another definition for heptads that I've seen is " Groups of seven".)