myriad
n. countablen. a very large number of something. You use it when you want to say there are so many things that they are hard to count.
n. an indefinitely great number; a vast multitude. Often used in the phrase 'a myriad of', though some style guides prefer it as a direct modifier.
The night sky was filled with a myriad of stars.
The new software update addresses a myriad of security concerns that users have reported over the last month.
The tropical rainforest is home to a myriad of species, many of which remain undiscovered by modern science due to the sheer density of the undergrowth.
From French myriade, from Late Latin mȳriadem (accusative of mȳrias), from Ancient Greek μυριάς (muriás, “number of 10,000”), from μυρίος (muríos, “numberless, countless, infinite”).
Commonly used in the construction 'a myriad of [plural noun]'. In formal writing, it is also used as an adjective directly before a noun ('myriad stars').