English Words: R

21,470 words · Page 313 of 430

Riekenname

A surname.

rielnoun

The monetary unit of Cambodia, equivalent to 100 sen or 10 kak. Symbol: ៛

Riemannname

A surname in German.

Riemann hypothesisname

The conjecture that the zeros of the Riemann zeta function exist only at the negative even integers and certain complex numbers whose real part is ½.

Riemann integralnoun

A type of integral whose computation involves dividing the interval of integration into smaller sub-intervals, summing sample values of the integrand inside those sub-intervals multiplied by their lengths, and letting the number of sub-intervals tend to infinity.

Riemann spherenoun

The complex numbers extended with the number ∞; the complex plane (representation of the complex numbers as a Euclidean plane) extended with a single idealised point at infinity and consequently homeomorphic to a sphere in 3-dimensional Euclidean space.

Riemann sumnoun

A certain kind of approximation of an integral by a finite sum that is calculated by dividing the interval of integration into smaller sub-intervals and summing sample values of the integrand inside those sub-intervals multiplied by their lengths.

Riemann surfacenoun

A one-dimensional complex manifold; a generalization of the complex plane.

Riemann zeta functionnoun

The function ζ defined by the Dirichlet series ζ(s)=∑ₙ₌₁ ᪲1/(nˢ)=1/(1ˢ)+1/(2ˢ)+1/(3ˢ)+1/(4ˢ)+⋯, which is summable for points s in the complex half-plane with real part > 1; the analytic continuation of said function, being a holomorphic function defined on the complex numbers with pole at 1.

Riemann-Lebesgue lemmanoun

A lemma, of importance in harmonic analysis and asymptotic analysis, stating that the Fourier transform or Laplace transform of an L1 function vanishes at infinity.

Riemann-Roch theoremname

An important theorem in complex analysis and algebraic geometry for the computation of the dimension of the space of meromorphic functions with prescribed zeros and allowed poles.

Riemann-Stieltjes integralnoun

A generalization of the Riemann integral, serving as a precursor of the Lebesgue integral and a means of unifying equivalent forms of statistical theorems that apply to discrete and continuous probability.

Riemannianadj

Of or relating to the work, or theory developed from the work, of German mathematician Bernhard Riemann, especially to Riemannian manifolds and Riemannian geometry.

Riemannian geometrynoun

The branch of differential geometry that concerns Riemannian manifolds; an example of a geometry that involves Riemannian manifolds.

Riemannian manifoldnoun

A real, smooth differentiable manifold whose each point has a tangent space equipped with a positive-definite inner product;

Riemername

A surname.

Riemersmaname

A surname from West Frisian.

riempienoun

A strip of worked leather, especially as used to form crisscrossed patterns on the back of chairs etc.

rien ne va plusphrase

In roulette, an announcement made by the croupier while the wheel is spinning and no more bets can be placed.

Riendeauname

A surname from French.

Riepl's lawname

The hypothesis that new forms of media never fully replace older ones, but rather the older forms find different ways or fields of use.

Rieraname

A surname.

Riesname

A surname from German.

Riesenname

A surname from German.

Riesenbergname

A surname from German.

Riesername

A surname.

Rieske proteinnoun

An iron-sulfur protein component of cytochrome complexes.

Rieslingnoun

A variety of grape grown especially in Germany and other relatively cool areas.

rieslingsnoun

plural of riesling; alternative spelling of Rieslings.

Riess spiralnoun

Either of a pair of spirally wound conductors with metal balls at their ends. Placing one above the other forms an induction coil.

Riesterername

A surname from German.

Rietavasname

A city and municipality of Telšiai, Lithuania.

rietboknoun

The antelope Redunca arundinum.

Rietiname

A province of Lazio, Italy.

Rietmannname

A surname from German.

Rietveldname

A surname from Dutch.

rietvelditenoun

A orthorhomic mineral containing iron, sulphur, hydrogen, oxygen, and uranium.

Rietzname

A surname from German.

rieveverb

Archaic form of reave.

rievernoun

Archaic form of reaver.

Rievesname

A surname.

RIFnoun

Initialism of reduction in force.

rifa-prefix

Used to form names of rifamycin derivatives used as antibiotics.

rifabutinnoun

A bactericidal antibiotic, primarily used in the treatment of tuberculosis, whose effect is based on blocking the DNA-dependent RNA-polymerase of the bacteria.

rifacimentonoun

A literary work or musical composition recast to adapt it to a change in the circumstances of the time.

rifaldazinenoun

rifampin

rifametanenoun

The antibiotic 3-azinomethyl-rifamycin.

rifamidenoun

Any amide of rifamycin.

rifampicinnoun

A reddish-brown semisynthetic antibiotic C₄₃H₅₈N₄O₁₂ obtained from the bacterium Amycolaptosis mediterranei, used chiefly to treat tuberculosis, leprosy, and asymptomatic carriers of meningococci.

rifampinnoun

US form of rifampicin.

Spelling & Dictionary Insight

The English alphabetical index for the letter R contains 21,470 headwords drawn from our Wiktionary-derived dictionary table. At 50 entries per page the browse splits into 430 pages, and you are currently viewing page 313. Every row above is a dictionary-backed entry with a canonical slug, and each links through to a full definition page with pronunciation, senses, etymology, and related-word data where available.

On this page 50 of 50 entries carry a part-of-speech tag and 50 carry at least one stored definition. Coverage varies across letters because Wiktionary volunteers build entries at different speeds for different parts of the alphabet, letters with common starting sounds (S, C, T, P) usually have the densest coverage, while less frequent starters (X, Q, Z) tend to have shorter but more specialised lists. PlainSpell surfaces whatever data is present and links back to the source when a definition is not yet recorded.

For readers using this index as a spelling reference, the guarantee is that every form you see on the list is a documented English headword, not a guess, not a derived inflection lacking a lemma row. If a word you expected to find is absent from the "R" list, it usually means the form exists only as an inflection of another lemma (e.g. a past participle stored under the infinitive) or the entry has not yet been imported from Wiktionary. Use the search bar or the misspelling lookup to resolve these cases.