Evanescent
Pronunciation : Ev`a*nes"cent
Part of Speech : a.
Etymology : [L. evanescens, -entis, p. pr. of evanescere.]
Definition : 1. Liable to vanish or pass away like vapor; vanishing; fleeting; as, evanescent joys. So evanescent are the fashions of the world in these particulars. Hawthorne.
2. Vanishing from notice; imperceptible. The difference between right and wrong, is some petty cases, is almost evanescent. Wollaston.
Source : Webster's Unabridged Dictionary, 1913