rayon

ray, beam (of light, etc.); spoke (of wheel); radius

From rai + -on. Unrelated to rayer.

honeycomb; shelf (for books, merchandise, etc.); department (of department store), section (of shop)

“Les importations de ces dernières semaines sont principalement des engrais, afin d'éviter un nouveau recul de la production agricole. Mais réapparaissent aussi, dans des magasins de Pyongyang, des produits non essentiels (chocolat, fruits séchés, etc.), qui avaient disparu des rayons.” — Imports in recent weeks are primarily fertilizers, in order to prevent a further decline in agricultural production. But non-essential products (chocolate, dried fruits, etc.), which had disappeared from the shelves, are also reappearing in the shops of Pyongyang.

Inherited from Middle French royon, rayon, from Old French raie, ree (“honeycomb”), from Frankish *hrātu (“honeycomb”). Etymology 2 sense 1 is original, but etymology 2 sense 2 coincidentally happens to be attested earlier.

row (for planting seeds in)

Inherited from Old French roion, reun, roïon. By surface analysis, raie + -on.