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English Words Starting With R

5,802 entries — pick a word to see its definition, pronunciation, and usage.

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Noun Verb Adjective Adverb Plural noun Combining form Verb (transitive)Verb (intransitive)Verb (ambitransitive)

rheopexy
nounVery low
/ˈriːəʊˌpɛksi/The property of certain fluids where viscosity increases with time under a constant applied shear stress.
rheoreceptor
nounC2/Highly Specialized
/ˌriːəʊrɪˈsɛptə/A sensory cell or organ that detects water currents.
rheostat
nounLow
/ˈriː.ə.stæt/A variable resistor used to control the flow of electric current by adjusting resistance.
rheotaxis
nounVery Low
/ˌriːəʊˈtæksɪs/The movement of an organism in response to a water current.
rheotron
nounExtremely Low
/ˈriːətrɒn/An early type of particle accelerator, specifically a betatron, used to accelerate electrons to high energies using a changing magnetic field.
rheotropism
nounC2
/riːˈɒtrəpɪz(ə)m/The directional growth or movement of an organism in response to a current of water or air.
rhesus
nounC1
/ˈriːsəs/A small, pale brown macaque monkey native to South and Southeast Asia, widely used in medical and biological research.
rhesus baby
nounLow
/ˈriːsəs ˌbeɪbi/A newborn infant with haemolytic disease caused by Rh factor incompatibility between the mother and the fetus.
rhesus factor
nounLow
/ˈriːsəs ˌfæktə/An antigen (specifically the D antigen) present on the surface of red blood cells in most people, which determines Rh blood group status.
rhesus monkey
nounLow to Medium
/ˈriːsəs ˌmʌŋki/A small, agile monkey (Macaca mulatta) with brownish fur and a pink face, native to South, Central, and Southeast Asia, widely used in biological and medical research.
rhetor
nounC2
/ˈriːtə/A teacher, master, or practitioner of rhetoric.
rhetoric
nounC1
/ˈretərɪk/The art or skill of speaking or writing effectively and persuasively.
rhetorical question
nounC1
/rɪˌtɒr.ɪ.kəl ˈkwes.tʃən/A question asked not to obtain an answer, but to make a point or create a dramatic effect.
rhetorical stress
nounC1-C2
/rɪˌtɒr.ɪ.kəl ˈstres/The intentional emphasis placed on a particular word or syllable within a sentence to convey meaning, emotion, or to guide an audience's interpretation, often used in public speaking, poetry, or persuasive discourse.
rhetorician
nounC1/C2
/ˌretəˈrɪʃn/An expert in or teacher of the art of rhetoric; a skilled public speaker or writer.
rheum
nounVery Low
/ruːm/A watery or thin mucous discharge from the eyes or nose, especially upon waking; the condition of having such a discharge.
rheumatic
adjectivenounLow-medium frequency, primarily in medical/older-generation contexts.
/ruːˈmætɪk/Relating to, suffering from, or characteristic of rheumatism, a disease causing pain and stiffness in the joints or muscles.
rheumatic fever
nounC2
/ruːˌmæt.ɪk ˈfiː.vər/A serious inflammatory disease, most often occurring in children, that can develop as a complication of an untreated streptococcal throat infection.
rheumatic heart disease
nounLow
/ruːˌmætɪk ˈhɑːt dɪˌziːz/A serious condition where the heart valves are permanently damaged by rheumatic fever, an inflammatory disease that can develop from a streptococcal infection.
rheumatics
nounC2
/ruːˈmætɪks/Painful medical conditions affecting joints, muscles, or connective tissue, often associated with stiffness and inflammation.

Showing 3481–3500 of 5802 words.