1
: angry or unhappy
I was feeling upset by/about the whole experience.
There's no point in getting all upset about it.
I try not to let her make me upset.
She was too upset to speak to him.
I'm upset that you didn't call.
I was so upset with him, I didn't call him for two weeks.
2
Note: If you have an upset stomach, you have an unpleasant feeling in your stomach because of illness or because of something you have eaten.
upsets; upset; upsetting
1
: to make (someone) unhappy, worried, etc.
That remark you made really upset me.
Don't upset yourself over it.
It upsets him that he can do nothing to help.
A lot of people were upset by the court's decision.
It upsets me to think I might never see him again.
2
: to cause an unpleasant feeling in (your stomach)
Spicy food upsets my stomach.
3
: to cause (something) to be unable to continue in the expected way
His sudden arrival upset [=disrupted] our plans.
4
: to defeat (someone who was expected to defeat you)
The heavyweight challenger upset the reigning champion in the third round.
She was upset in the primary.
5
: to cause (something) to fall
He accidentally bumped the table and upset a lamp.
plural upsets
1
: an occurrence in which a game, contest, etc., is won by a person or team that was expected to lose
In a major upset, he took the gold medal.
Her victory in the election was a big upset.
an upset victory
2
: an unpleasant feeling of illness in your stomach
Spicy foods can cause stomach upset.
a minor stomach upset
3
: a period of worry and unhappiness caused by something that has happened
An emotional upset can affect your physical health.
a period of emotional upset
Cite this Entry
“Upset.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/upset. Accessed 20 Jun. 2026.
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