- 1[countable] (in a competition) a situation in which a person or team beats the person or team that was expected to win
- 2[countable] an illness in the stomach that makes you feel sick or have diarrhea a stomach upset
- 3[uncountable] a situation in which there are problems or difficulties, especially when these are unexpected The company has survived the recent upset in share prices. His health has not been improved by all the upset at home.
- 4[uncountable, countable] feelings of unhappiness and disappointment caused by something unpleasant that has happened It had been the cause of much emotional upset.