Definitions (from Oxford English Dictionary):
ephemera (n.): 1. An insect that (in its imago or winged form) lives only for a day. In mod. entomology the name of a genus of pseudo-neuropterous insects belonging to the group Ephemeridæ (Day-flies, May-flies). 2. transf. and fig. One who or something which has a transitory existence.
ephemeral (adj.): 1.b. Of insects, flowers, etc.: Existing for one day only, or for a very few days. 2.a. In more extended application: That is in existence, power, favour, popularity, etc. for a short time only; short-lived; transitory.
evanescent (adj.) [
1. That is on the point of vanishing or becoming imperceptible. In Mathematics, said of a diminishing quantity: That is at the instant of becoming zero; infinitesimal. Hence transf. of things: Imperceptibly minute, too small to perceive.
2. That quickly vanishes or passes away; having no permanence. Said of appearances, conditions, impressions, etc.
verb to evanesce: To fade out of sight, ‘melt into thin air’, disappear; chiefly fig. Also in scientific use . . . of the edge of a polyhedron when two adjacent faces are made to rotate into one plane.
7. Of a person: having a
lively, volatile, or restless nature; liable to sudden and unpredictable changes
of mind or mood; quick-witted, imaginative. Later also gen. (applied to
animals, phenomena, etc.,): changeable, unpredictable, fickle.
1.a. Passing by or away with time; not durable or permanent; temporary, transitory; esp. passing away quickly or soon, brief, momentary, fleeting
4. Passing through a place without staying in it, or staying only for a short time; in quot. 1731 of birds, migratory; spec. (U.S. colloq.) applied to a guest at a hotel, etc. (often ellipt. as n.: see B. 2). Also transf., for transient guests, short-stay.
These terms describe a fleeting or barely-glimpsed reality. Some examples:
. . A color stands abroad
Hawthorne, The Minister's Black Veil: Father Hooper's breath heaved . . . . He even raised himself in bed; and there he sat, shivering with the arms of death around him, while the black veil hung down, awful, at that last moment, in the gathered terrors of a life-time. And yet the faint, sad smile, so often there, now seemed to glimmer from its obscurity, and linger on Father Hooper's lips.
VIII . . . Like a dull scholar, I behold, in love,
An ancient aspect touching a new mind.
It comes, it blooms, it bears its fruit and dies.
This trivial trope reveals a way of truth.
Our bloom is gone. We are the fruit thereof. . . .
XII A blue pigeon it is, that circles the blue sky,
On sidelong wing, around and round and round.
A white pigeon it is, that flutters to the ground,
Grown tired of flight. Like a dark rabbi, I
Observed, when young, the nature of mankind,
In lordly study. Every day, I found
Man proved a gobbet in my mincing world. [gobbet=portion of meat; mince=cut in small pieces; speak or think in an over-refined way]
Like a rose rabbi, later, I pursued,
And still pursue, the origin and course
Of love, but until now I never knew
That fluttering things have so distinct a shade.