Study is gloomy and yet exotic (9)
I believe the answer is:
etymology
'study' is the definition.
(etymology is a kind of study)
'gloomy and yet exotic' is the wordplay.
'and' says to put letters next to each other.
'exotic' indicates anagramming the letters (an unusual form of the letters).
'gloomy'+'yet'='gloomyyet'
'gloomyyet' with letters rearranged gives 'ETYMOLOGY'.
'is' is the link.
(Other definitions for etymology that I've seen before include "Study of the derivation of words" , "Study of the development of words" , "Original root" , "Study of origin of words" , "story in a word?" .)