Puzzle even disheartened one grandmother, briefly (6)
I believe the answer is:
enigma
'puzzle' is the definition.
(I've seen this in another clue)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for enigma that I've seen before include "Coding device" , "Elgar Variations nickname" , "'Mystery, riddle (6)'" , "Something mysterious and puzzling" , "There's a mystery in game" .)