myriad

Etymology

From French myriade, from Late Latin myriadem (accusative of myrias), from Ancient Greek μυριάς (muriás, “number of 10,000”), from μυρίος (muríos, “numberless, countless, infinite”).

noun

1. (historical) Ten thousand; 10,000
2. A countless number or multitude (of specified things)
   Earth hosts a myriad of animals.
   How far he surpassed them all may be felt if we remember that no Scythian, although the Scythians are reckoned by their myriads, has ever succeeded in dominating a foreign nation ... 1914, Henry Graham Dakyns, Xenophon, Cyropaedia, Book I

adj

1. (modifying a singular noun) Multifaceted, having innumerable elements
   one night he would be singing at the barred window and yelling down out of the soft myriad darkness of a May night; the next night he would be gone …. 1931, William Faulkner, Sanctuary, Vintage, published 1993, page 131
   "As a clinician, it's a difficult symptom to treat," Cornelius said. "The end symptom may be the same, but what's causing it may be myriad." 2011 April 6–19, Kara Krekeler, "Researchers at Washington U. have 'itch' to cure problem", West End Word, 40 (7), p. 8
2. (modifying a plural noun) Great in number; innumerable, multitudinous
   Earth hosts myriad animals.
   Driven by a perceived political need to adopt a hard-line stance, Mr. Cameron’s coalition government has imposed myriad new restrictions, the aim of which is to reduce net migration to Britain to below 100,000. September 28 2013, Kenan Malik, “London Is Special, but Not That Special”, in New York Times, retrieved 2013-09-28