Savoury flavour (5)
I believe the answer is:
umami
'savoury flavour' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for umami that I've seen before include "Newly discovered taste" , "Fifth flavour" , "meaty taste" , "Savoury flavour" , "Japanese word for pleasant savoury taste" .)