Sums about missing beings (8)
I believe the answer is:
entities
'beings' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for entities that I've seen before include "Things with seperate existence, objects" , "They exist as separate things" , "Beings" , "Things that have physical existence" , "Things that have a separate existence" .)