lightspeed

1 synonym for lightspeed, grouped by meaning and by how common each one is.

Noun — The speed at which light travels, usually through a vacuum.

Synonyms

Rare, literary or technical

Precise, but they will stand out — check the sense before using one.

speed of light

Synonyms by Meaning

1. noun

The speed at which light travels, usually through a vacuum.

“The probe's onboard computer calculated the signal delay at lightspeed.”

speed of light

2. noun colloquial

A very high speed, used to describe something moving or happening extremely quickly.

“The news spread across the office at lightspeed.”

speed of light

How to use lightspeed

The word patterns that sound natural to a native speaker.

travel at lightspeed faster than lightspeed at lightspeed approach lightspeed

The figurative sense is informal and suits everyday or conversational writing rather than formal scientific text.

Etymology

Formed within English by combining the word light with the word speed. The compound describes the rate at which light travels and, by extension, any comparably fast rate.

Full origin of lightspeed →

Frequently asked questions

What does lightspeed mean?

It refers to the speed of light, or informally to something happening extremely fast.

Is lightspeed one word or two?

It is commonly written as one word, lightspeed, though light speed as two words is also used.

Can lightspeed be used figuratively?

Yes, it is often used colloquially to describe something that happens or moves very quickly, not literally at the speed of light.

Nearby words

← Back to the full definition of lightspeed