An Etymological Dictionary of Astronomy and Astrophysics

The gradual reduction in energy through an optical system as the off-axis angle increases, resulting from limitations of the clear apertures of elements within the system.

Etymology (EN): From vignette “an unbordered picture, often a portrait, that shades off into the surrounding color at the edges;” “softening the edges of a picture in vignette style;” from Fr. vignette, O.Fr., diminutive of vigne “vineyard;” from L. vinea “vine, vineyard,” from vinum “wine.”

Etymology (PE): Labe-puš, literally “limb covering,” from labé “limb,” from lab “lip;” (Mid.Pers. lap; cf. L. labium; O.E. lippa; E. lip; Ger. Lefze) + puš present stem of pušidan “to cover; to put on” (Mid.Pers. pôšidan, pôš- “to cover; to wear;” cf. Mid.Pers. pôst; Mod.Pers. pust “skin, hide;” O.Pers. pavastā- “thin clay envelope used to protect unbaked clay tablets;” Skt. pavásta- “cover,” Proto-Indo-Iranian *pauastā- “cloth”).