monetary adj.

mid-13c., monie, "funds, means, anything convertible into money;" c. 1300, "coinage, coin, metal currency," from Old French monoie "money, coin, currency; change" (Modern French monnaie), from Latin moneta "place for coining money, mint; coined money, money, coinage," from Moneta, a title or surname of the Roman goddess Juno, near whose temple on the Capitoline Hill money was coined (and in which perhaps the precious metal was stored); from monere "advise, warn, admonish" (on the model of stative verbs in -ere; see monitor (n.)), by tradition with the sense of "admonishing goddess," which is sensible, but the etymology is difficult. A doublet of mint (n.2)).

It had been justly stated by a British writer that the power to make a small piece of paper, not worth one cent, by the inscribing of a few names, to be worth a thousand dollars, was a power too high to be entrusted to the hands of mortal man. [John C. Calhoun, speech, U.S. Senate, Dec. 29, 1841] 

Extended by early 19c. to include paper recognized and accepted as a substitute for coin. The highwayman's threat your money or your life is attested by 1774. Phrase in the money (1902) originally referred to "one who finishes among the prize-winners" (in a horse race, etc.). The challenge to put (one's) money where (one's) mouth is is recorded by 1942 in African-American vernacular. Money-grub for "avaricious person, one who is sordidly intent on amassing money" is from 1768; money-grubber is by 1835. The image of money burning a hole in someone's pocket is attested from 1520s (brennyd out the botom of hys purs).

I am not interested in money but in the things of which money is the symbol. [Henry Ford]

1914, "of a monetary character or having a monetary basis," from monetary + -ist. As a noun, "one who advocates tight control of the money supply to remedy inflation," by 1963. Related Monetarism (1963).