Mysteries (7)
'mysteries' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for arcana that I've seen before include "Secret things" , "Tarot cards" , "Secrets, mysteries" .)
'mysteries' is the definition.
('enigma' can be a synonym of 'mystery')
This is all the clue.
(Other definitions for enigmas that I've seen before include "'Mysteries, riddles (7)'" , "'Puzzles, riddles (7)'" , "They're mysterious or difficult to understand" , "Puzzles - mysteries" , "Problems" .)