Wiktionary
n. (context physics English) Any particle with non-zero mass (i.e. one that travels more slowly than the speed of light).
Usage examples of "tardyon".
Gravitational waves laid hold of the tachyons which sprang into being, paired with tardyons, and formed them into a beam, and modulated it.
In other words, tachyons and tardyons must coexist everywhere and are merely different expressions of identical phenomena.
The computers might calculate the exact quantity and timing of the energy input and the exact place and direction (if “direction “ had any meaning in the transition from tardyon to tachyon), but the margin of error was huge and only a talented Fusionist could lower it.
Our world, in which the speed of light is the upper limit of velocity, is one inertial system, but the world of tachyons, luxons and tardyons with a velocity faster than light is another inertial system.