An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) To disappear from sight, especially quickly; become invisible.
2) To disappear by ceasing to exist; come to an end.
3) Math.: To become zero or to tend to zero.

M.E., from O.Fr. esvanir "disappear; cause to disappear," from L. evanescere "disappear, pass away, die out," from → ex- "out" + vanescere "to vanish," from vanus "empty," cognate with O.E. wanian "to lessen," wan "deficient;" O.N. vanta "to lack;" L. vacare "to be empty," vastus "empty, waste;" see below for Iranian cognates.

Venidan, from Kurd. ven "missing; away; absent," cf. Pers. vang "empty, empty-handed, poor;" related to Av. ūna- "deficient, empty," ū- "to be incomplete;" akin to Skt. vā- "to disappear, diminish," ūná- "deficient;" L. vanus "empty," as above.