Search Dictionary
Definition of lightspeed

lightspeed

/ˈlaɪt.spiːd/
light · speed
JUMP TO:

lightspeed Lexical Profile

lightspeed Game Scores & Validity

• noun

1

The speed at which light travels in a vacuum, approximately 299,792 kilometers (186,282 miles) per second.

Example

"According to the theory of relativity, no object with mass can accelerate all the way to lightspeed."

2

An extremely rapid or seemingly instantaneous rate of movement, progress, or change.

Example

"Technological innovation has been advancing at lightspeed over the past two decades."

Synonyms
View all synonyms for lightspeed
Antonyms
View all antonyms for lightspeed

• adjective

1

Moving, operating, or occurring at the speed of light, or figuratively at an extremely fast rate.

Example

"Modern fiber-optic networks enable lightspeed data transmission across continents."

Synonyms
View all synonyms for lightspeed
Antonyms
View all antonyms for lightspeed

• Nearby Words

lightproof
lights
lightsaber
lightspeed
lightweight
ligularia
ligustrum

Usage Trend

Historical frequency of usage in published text.

180019102020
Data source: Google Books Ngram Viewer

Cite this Entry

Wordmom. (2026). Definition of Lightspeed. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/lightspeed
Built for writers, students, and competitive word game players, Wordmom combines an uncluttered English dictionary and thesaurus with fast, pattern-based word finders so you can verify definitions, synonyms, and high-scoring tile plays in one place.
Word Games & Solvers
Word FinderScrabble Word FinderWords With Friends CheatWordle SolverAnagram Solver
Dictionary & Reference
DictionarySynonymsAntonymsWords
Community
Contact UsEditorial PolicyPrivacy PolicyTerms and Conditions
© 2016–2026 Wordmom Network. All rights reserved. Made with for word lovers everywhere.
Disclaimer: SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A. and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. Words With Friends® is a registered trademark of Zynga Inc. Wordle® is a registered trademark of The New York Times Company. Other referenced game titles and tournament lexicon codes (including NASPA NWL and WESPA/HarperCollins CSW) are trademarks of their respective owners. Wordmom is an independent reference utility for educational and entertainment purposes and is not affiliated with, sponsored by, or endorsed by Hasbro, Mattel, Spear, Zynga, The New York Times Company, NASPA, WESPA, or HarperCollins Publishers. All game names are referenced strictly under nominative fair use to indicate compatibility.