radi
Latinray, spoke, radius (rays spreading out from a centre)
About This Root
From Latin radius 'ray of light, spoke of a wheel, rod' and the verb radiare 'to emit rays.' The image of lines fanning out from a centre connects geometry (radius, radial), light and energy (radiate, radiation, radiant, radium), and even fabric (rayon, named for its sheen).
Associated Words · 9
radiation
Energy emitted as rays, waves, or particles
radiate
To emit rays or spread outward from a centre
radius
The distance from centre to edge of a circle; the forearm bone on the thumb side
radiant
Emitting light or heat; beaming with happiness
radiator
A heating or cooling device that transfers heat
radial
Arranged like rays from a centre (adj.); a radial tyre (n.)
rayon
A soft synthetic silk-like fabric
irradiate
To expose to radiation; to illuminate with light
radium
A highly radioactive metallic element, symbol Ra