relativistic

American  

[rel-uh-tuh-vis-tik] / ˌrɛl ə təˈvɪs tɪk /

adjective

1. of or relating to relativity or relativism.

2. Physics.

   1. subject to the special or the general theory of relativity.

   2. (of a velocity) having a magnitude that is a significant fraction of the speed of light.

   3. (of a particle) having a relativistic velocity.

      radiation from relativistic electrons.

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relativistic British  

/ ˌrɛlətɪˈvɪstɪk /

adjective

1. physics having or involving a speed close to that of light so that the behaviour is described by the theory of relativity rather than by Newtonian mechanics

   a relativistic electron

   a relativistic velocity

2. physics of, concerned with, or involving relativity

3. of or relating to relativism

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Other Word Forms

• ultrarelativistic
  adjective
• unrelativistic
  adjective
• relativistically
  adverb

Etymology

Origin of relativistic

First recorded in 1885–90; relativist + -ic

Example Sentences

See Examples For:

relativistic

As binary stars slowly spiral closer over time, relativistic effects become more important.

From Science Daily ● Apr. 19, 2026

Black holes in binary systems pull in matter from companion stars, creating relativistic jets that transform these systems into "micro-quasars."

From Science Daily ● Nov. 16, 2025

Their picture shows the galaxy NGC 5128 and its relativistic jet - beams of radiation and particles travelling close to the speed of light.

From BBC ● Sep. 12, 2024

On the other end of the spectrum, hot dark matter moves at relativistic speeds, rendering it incapable of gathering most anything.

From Scientific American ● Jun. 20, 2023

McMillan and Alvarez returned from Los Alamos impatient to try out new approaches they had conceived to address that old bugaboo, the relativistic barrier to higher energies.

From "Big Science" by Michael Hiltzik