evanescent \ev-uh-NES-uhnt\, adjective:
Liable to vanish or pass away like vapor; fleeting.
The Pen which gives. . . permanence to the evanescent
thought of a moment.
--Horace Smith, Tin Trumpet
Every tornado is a little different, and they are all
capricious, evanescent and hard to get a fix on.
--"Oklahoma Tornado Offers Hints of How a Killer Storm Is
Born," New York Times, May 11, 1999
The accidentally famous. . . may write books, appear on
talk shows, and, in so doing, attract even greater public
attention. This type of celebrity status, of course, is
brittle and evanescent.
--Lawrence M. Friedman, The Horizontal Society
Evanescent is from Latin evanescere, "to vanish," from e-,
"from, out of" + vanescere, "to disappear," from vanus,