D defs.my
Entry 2 senses Webster, 1913

Evanescent

/ĕvˌ-ən-ĕs'-ənt/ · Ev·a·nes·cent · IPA /ˌɛvəˈnɛsənt/
01 a. Liable to vanish or pass away like vapor; vanishing; fleeting; as, evanescent joys.
  1. 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. 2.
    Vanishing from notice; imperceptible.
    “The difference between right and wrong, in some petty cases, is almost evanescent.” — Wollaston.