An Etymological Dictionary of Astronomy and Astrophysics

Not bright; obscure from lack of light.

Etymology (EN): O.E. dimm “dark, gloomy, obscure,” from P.Gmc. *dimbaz.

Etymology (PE): Tiré, from Mid.Pers. têrag, variant of târig “dark,”
Av. taθra- “darkness,” taθrya- “dark,” cf. Skt. támisrâ- “darkness, dark night,” L. tenebrae “darkness,” Hittite taš(u)uant- “blind,” O.H.G. demar “twilight.”