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Synonyms

hyper

1 American  
[hahy-per] / ˈhaɪ pər /

adjective

  1. overexcited; overstimulated; keyed up.

  2. seriously or obsessively concerned; fanatical; rabid.

    She's hyper about noise pollution.

  3. hyperactive.

noun

  1. a person who is hyper.

hyper 2 American  
[hahy-per] / ˈhaɪ pər /

noun

Informal.

  1. a person who promotes or publicizes events, people, etc., especially one who uses flamboyant or questionable methods; promoter; publicist.

hyper- 3 American  

  1. a prefix appearing in loanwords from Greek, where it meant “over,” usually implying excess or exaggeration (hyperbole ); on this model used, especially as opposed to hypo-, in the formation of compound words (hyperthyroid ).

hyper- 1 British  

prefix

  1. above, over, or in excess

    hypercritical

  2. (in medicine) denoting an abnormal excess

    hyperacidity

  3. indicating that a chemical compound contains a greater than usual amount of an element

    hyperoxide
"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
hyper 2 British  
/ ˈhaɪpə /

adjective

  1. informal overactive; overexcited

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
hyper– Scientific  

  1. A prefix that means “excessive” or “excessively,” especially in medical terms like hypertension and hyperthyroidism.

Etymology

Origin of hyper1

First recorded in 1970–75; probably independent use of hyper-

Origin of hyper2

1910–15, for an earlier sense; hype 1 + -er 1

Origin of hyper-3

Greek, representing hypér over, above; cognate with Latin super ( super- ); akin to over

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

In this room, I am at times unsettled, at once tracking the movements of the actors while attempting to remain hyper aware of any sudden touch or scent.

From Los Angeles Times • Mar. 26, 2026

"What it's forced everybody to do is to be hyper vigilant about the news," said Interactive Brokers analyst Steve Sosnick.

From Barron's • Mar. 6, 2026

When the Sun gets all hyper with magnetic activity, it throws out huge bursts of super-hot, super-fast gas called plasma.

From Space Scoop • Nov. 19, 2025

Side effects are rare, but some children get a little more hyper or have more repetitive behaviors.

From The Wall Street Journal • Sep. 24, 2025

You need to stop getting so hyper and take things more calmly.

From "Our America: Life and Death on the South Side of Chicago" by LeAlan Jones

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.