informal
: very excited, nervous, or active
a hyper [=hyperactive] kid
I get a little hyper when I drink too much coffee.
ˈhaɪpɚ
1
: excessively or extremely
hyperactive
hypersensitive
2
: excessive or extreme
hypersensitivity
hypertension
Cite this Entry
“Hyper.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/hyper. Accessed 18 Jun. 2026.
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