Definition of "conversely"

If two parallelograms, which have one angle of the one equal to one angle of the other, be equal to one another, the sides about the equal angles are reciprocally proportional, and conversely.

1784, John West, “[Elements of Geometry.] Proposition VIII.”, in Elements of Mathematics. […], Edinburgh: Printed for William Creech; and sold in London by T[homas] Longman and T[homas] Cadell., book V (Definitions), page 127

Proposition I. If four quantities are proportional, the product of the extremes is equal to the product of the means, and conversely.

1860, Benjamin Greenleaf, “Section XIX. Ratios.”, in A Practical Treatise on Algebra, page 207

Glasses (perspicua) can be so constructed that objects at a very great distance appear to be quite close at hand, and conversely. Thus we read the smallest letters from an incredible distance, number objects, however small, and make the stars appear as near as we wish. … Also objects can be made to appear so that the greatest seems the least, and conversely; what are high appear low and short, and conversely; and what is hidden appears manifest. … [translation of Roger Bacon's De Secretis Operibus Artis et Naturae.]

1921, Charles Singer, “Steps Leading to the Invention of the First Optical Apparatus”, in Charles Singer, editor, Studies in the History and Method of Science, volume II, Oxford: At the Clarendon Press, page 398

In these cases the market has sufficient skepticism as to the continuation of the unusually high profits to value them conservatively, and conversely when earnings are low or nonexistent.

1949, Benjamin Graham, The Intelligent Investor: A Book of Practical Counsel, New York, N.Y.: Harper & Brothers, page 165

As for the ability for a nation to finance in the international market, if the nation has a relatively good reputation in the international financial market, then the nation can quickly and conveniently obtain loans from foreign governments and international financial institutions with stable sources of funds. In this case, the nation does not need to maintain a large scale of international reserve. Conversely, if a nation's credit rating is low, the nation will have difficulty to raise funds. In this case, the nation will need more sufficient international reserve.

2014, Jeffrey Yi-Lin Forrest, “International Reserves and Capital Flows”, in A Systems Perspective on Financial Systems (Communications in Cybernetics, Systems Science and Engineering; 6), Boca Raton, Fla., London: CRC Press/Balkema, section 9.2.1 (The Management of Magnitudes), page 354

[R]esearch has found that social integration is more important for well-being than income, and also decreases poverty. Loneliness, conversely, can be deadly: one study found it did more damage to health than smoking.

2015 June 4, “With a little help from my friends: Poverty is about who you know as much as what you earn”, in The Economist‎, archived from the original on 6 November 2018

At 123 yards, Royal Troon's par-3 eighth in the shortest hole in the Open Championship rota. Known as the "Postage Stamp," the eighth's distance has produced plenty of aces – most recently, Ernie Els in 2004, but Gene Sarazen's hole-in-one remains the benchmark, as the Squire accomplished said feat at 71 years old. Conversely, the hole is not a walk in the park.

2016 July 12, Joel Beall, “Watch Rory McIlroy Make a 9 at Royal Troon’s Postage Stamp”, in Golf Digest‎, archived from the original on 15 November 2016

So the issue of unification only comes up when the geometry can no longer be treated as a mere background, or conversely, when the classical theory is no longer accurate. But these circumstances exist (as far as we know) in only two places: the earliest moments of the Big Bang, and the immediate vicinity of singularities hidden behind black hole event horizons.

2017 April 13, Viktor T. Toth, “Why Do General Relativity and Quantum Mechanics Need to be Unified?”, in Forbes‎, archived from the original on 6 November 2018

We live in a time when roughly half of the jobs in 2020 are not yet known to us, and conversely, half of the jobs today will be extinct.

2017 April 17, Derrick Chang, “What skills does Singapore need for the future economy?”, in Today‎, archived from the original on 17 April 2017

[R]abbits, as it turns out, are rather like children. You can read all the books you want, but you have no idea how much trouble they are – or, conversely, how cute they can be – before you actually plunge in at the deep end.

2017 July 8, James Baldock, “17 things no one tells you before you get a rabbit”, in Metro‎, archived from the original on 26 September 2018