I saw in a New York Times article the following sentence...
Earlier this month, the Biden administration blocked access to myriad websites linked to Iran after the nation held a presidential vote to install Mr. Raisi, a close ally of the clerical government’s supreme leader, as its top elected official.
I was expecting this sentence to say "a myriad of" but being the New York Times I knew I had something to learn.
A quick look at the Oxford Dictionary of American English revealed this definition and USAGE note. As you can see below, both noun and adjective uses are "equally standard and correct" Very interesting. So, from now on, I will be a pontificating "traditionalist" when it comes to this word.
myr·i·ad| ˈmirēəd |
literary noun
1
a countless or extremely great number: networks connecting a myriad of computers.
2
(chiefly in classical history) a unit of ten thousand: the army was organized on a decimal system, up to divisions of 10,000 or myriads.
adjective
countless or extremely great in number: the myriad lights of the city.
• having countless or very many elements or aspects: the myriad political scene.
USAGE
Myriad is derived from a Greek noun and adjective meaning ‘ten thousand.’ It was first used in English as a noun in reference to a great but indefinite number. The adjectival sense of ‘countless, innumerable’ appeared much later. In modern English, use of myriad as a noun and adjective are equally standard and correct, despite the fact that some traditionalists consider the adjective as the only acceptable use of the word. ORIGIN mid 16th century (in myriad (sense 2 of the noun)): via late Latin from Greek murias, muriad-, from murioi ‘10,000’.