Not happy (5)
'not happy' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for upset that I've seen before include "Make unhappy; knock over" , "Distressed - surprise" , "Overturn - worry" , "Unexpected defeat - tipped over" , "Caused grief" .)
'not happy' is the definition.
('sad' is the opposite to 'happy')
This is the entire clue.
(Other definitions for sad that I've seen before include "Downcast" , "Tragic" , "Heavy-hearted" , "Disconsolate" , "Unhappy or melancholy" .)