of the first order

Related to of the first order: First order reaction, First order logic, Pseudo first order reaction

of the first order

Of the greatest importance, significance, or magnitude. You have to study Shakespeare because he is a poet of the first order. We need to close the highway immediately—this is an emergency of the first order.
See also: first, of, order
Farlex Dictionary of Idioms.

of the first order (or magnitude)

used to denote something that is excellent or considerable of its kind.
In astronomy, magnitude is a measure of the degree of brightness of a star. Stars of the first magnitude are the most brilliant.
See also: first, of, order
Farlex Partner Idioms Dictionary

of the highest/first ˈorder

,

of a high ˈorder

of the best, worst, most extreme, etc. type: It was a scandal of the first order.
See also: first, high, of, order
Farlex Partner Idioms Dictionary

first magnitude/order/water, of the

The best; of the highest quality. Magnitude refers to the grading of the brightness of stars, the first being the brightest. It has been transferred to other matters since at least the seventeenth century. “Thou liar of the first magnitude,” wrote William Congreve in 1695 (Love for Love, 2.2). Water refers to a system for grading diamonds for their color or luster (the latter being akin to the shininess of water), the best quality again being termed the first. This grading system is no longer used, but the transfer to other matters has survived since the early nineteenth century. Sir Walter Scott’s journal has, “He was a . . . swindler of the first water (1826). Order, which here refers to rank, is probably more often heard today than either of the others. It dates from the nineteenth century. The OED cites “A diplomatist of the first order,” appearing in a journal of 1895. A synonymous term, first rate, originated from the time the Royal Navy’s warships were rated on a scale of one to six, based on their size and the weight of the weapons they carried. By the 1700s this term, along with second-rate, third-rate, and so on, was later transferred to general use, most often as a hyphenated adjective. For example, “He’s definitely a second-rate poet, nowhere near as good as his father.”
See also: first, magnitude, of, order
The Dictionary of Clichés by Christine Ammer
See also:
  • of the highest/first order
  • of the highest order
  • of the first magnitude
  • first magnitude/order/water, of the
  • magnitude
  • of the highest magnitude
  • there is no there there
  • of great moment
  • of moment
  • rate with (someone or something)
References in periodicals archive
CF in the neighbourhood of the first order real critical point is presented in Figure 10.
Spectrum Curves for Sturm--Liouville Problem with Integral Boundary Condition
Rove, who is about two semesters short of his bachelor's degree in political science, is no economist but is a policy wonk of the first order and understands the details of the issues.
Who is behind Bush economic policy? Check out the Ward Room of the White House
Frances Cress Welsing is "an intellectual buffoon of the first order." Now, if that isn't enough to infuriate true believers, the acerbic critic has more put-downs for black athletic "knot-heads" and "imbecilic" Farrakanians and Sharptonites.
The Artificial White Man: Essays on Authenticity
Hardy barely has the first sentence out of his mouth before the listener knows that this is British satire of the first order. Maybe it takes another sentence or two before we know we are in what was known as the Roaring 20s in the States.
Vile Bodies