Study of flying saucers (7)
I believe the answer is:
ufology
'study' is the definition.
(I have seen 'Study of exotica' mean 'ufology' so perhaps 'study' could also mean 'ufology')
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for ufology that I've seen before include "Study of exotica" , "Study of (supposedly) alien craft" , "Study of weird things in sky" , "New world for the study of flying saucers" , "Formal study of flying saucers" .)