shimmer

Etymology 1

From Middle English schimeren, from Old English sċymrian, sċimrian, sċimerian, from Proto-Germanic *skimarōną. Cognate with Dutch schemeren, German schimmern.

verb

1. (intransitive) To shine tremulously or intermittently; to gleam faintly.
   1581, John Studley (translator), Medea, Act 4, in Seneca his Tenne Tragedies, London: Thomas Marsh, p. 135, With dusky shimmering wanny globe, her lampe doth pale appeare
   The shimmering glimpses of a stream 1850, Alfred Tennyson, The Princess: A Medley, 3rd edition, London: Edward Moxon, Conclusion, p. 173
   I looked then and saw that his robes, which had seemed white, were not so, but were woven of all colours, and if he moved they shimmered and changed hue so that the eye was bewildered. 1954, J. R. R. Tolkien, The Fellowship of the Ring, New York: Ballantine Books, published 1973, Book 2, Chapter 2, p. 339
   Pale tourists, tired but excited, emerge like apparitions from the heat haze that shimmers over the tarmac. 2018, Tsitsi Dangarembga, chapter 22, in This Mournable Body, Minneapolis: Graywolf Press

noun

1. A faint or veiled and tremulous gleam or shining.
   The hives […] were scattered towards the back of the clearing, like small mounds of clean vegetable refuse. Over each mound there hung a dusty golden shimmer of bees. 1922, Katherine Anne Porter, “María Concepción”, in Flowering Judas and Other Stories, New York: The Modern Library, published 1940, page 6
   He’d aimed film lamps at the rectangular pools, which sent reflections up the gallery wall in veined and fractured shimmers. 2013, Rachel Kushner, chapter 16, in The Flamethrowers, New York: Vintage, published 2014, page 294
2. (signal processing) A measure of the irregularities in the loudness of a particular pitch over time.
   Coordinate term: jitter
   As such, perturbation measures can only be derived from vowels, most accurately, sustained vowels or steady-state portions of vowels extracted from connected speech. Two commonly obtained perturbation measures are jitter and shimmer. 2010, Daniel R. Boone, The Voice and Voice Therapy, Pearson College Division

Etymology 2

shim + -er

noun

1. (crime) A thin electronic device that is fit inside a card reader, such as on automated teller machines (ATMs), or point-of-sale terminals (POS's), that acts as an intermediate interface between the chip on a chip-and-pin technology card and the chip reader of the machine, to allow one to clone the chip.