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ultrafast

American  
[uhl-truh-fast, -fahst] / ˌʌl trəˈfæst, -ˈfɑst /

adjective

  1. extremely fast.

    ultrafast computers.
ultrafast British  
/ ˈʌltrəˌfɑːst /

adjective

  1. extremely fast

    an ultrafast internet connection
"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

Etymology

Origin of ultrafast

ultra- + fast 1

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.

XTX has lobbied for speed bumps—tiny delays to thwart ultrafast traders—angering some competitors.

From The Wall Street Journal • Apr. 23, 2026

To address this, the team aims to combine CST-CMFI with compressive ultrafast photography.

From Science Daily • Apr. 21, 2026

Researchers have created a powerful new imaging method that reveals far more detail about ultrafast events in the microscopic world than ever before.

From Science Daily • Apr. 21, 2026

Since each wavelength represents a specific moment, the result is a sequence of frames that forms an ultrafast movie captured in a single shot.

From Science Daily • Apr. 21, 2026

What would happen if that alien horror simply slashed out with one ultrafast hand and showed Colonel Mannheim and all his watching technicians that they had completely underestimated his alien ability?

From Anything You Can Do ... by Garrett, Randall

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.