An Etymological Dictionary of Astronomy and Astrophysics

The property of certain crystals of exhibiting different colors when viewed from different directions under transmitted light. This is because the degree with which
certain birefringent crystals transmit polarized light is different, depending on whether the ray is ordinary or extraordinary. Pleochroism is the general term for both dichroism, which is found in uniaxial crystals (crystals with a single optic axis), and trichroism, found in biaxial crystals (two optic axes).

Etymology (EN): From pleochro(ic), from pleo- prefix meaning “more,” from Gk. pleion “more,” cognate with Pers. por, → full,

• chroic, from chroos “skin, color” + -ism.

Etymology (PE): Candfâmi, from cand “so many, much; how many, how much” (O.Pers. yāvā “as long as;” Av. yauuant- [adj.] “how great?, how much?, how many?,” yauuat [adv.] “as much as, as far as;” cf. Skt. yāvant- “how big, how much;” Gk. heos “as long as, until”) + fâm “color,” + -i noun suffix.