| aldotetrose | (noun) A four-carbon aldose; for example, threose, erythrose. | - |
|---|
| ametropia | (noun) (ophthalmology) faulty refraction of light rays in the eye as in astigmatism or myopia | - |
|---|
| anisometropia | (noun) difference in the refractive power of the two eyes | - |
|---|
| beetroot | (noun) round red root vegetable | Synonyms: beet |
|---|
| (noun) beet having a massively swollen red root; widely grown for human consumption | Synonyms: Beta vulgaris rubra |
| betrothal | (noun) the act of becoming betrothed or engaged | Synonyms: espousal |
|---|
| (noun) a mutual promise to marry | Synonyms: engagement, troth |
| betrothed | (noun) the person to whom you are engaged | - |
|---|
| dimetrodon | (noun) carnivorous dinosaur of the Permian in North America having a crest or dorsal sail | - |
|---|
| emmetropia | (noun) (ophthalmology) the normal refractive condition of the eye in which there is clear focus of light on the retina | - |
|---|
| globetrotter | (noun) someone who travels widely and often | Synonyms: world traveler |
|---|
| hypermetropia | (noun) abnormal condition in which vision for distant objects is better than for near objects | Synonyms: farsightedness, hypermetropy, hyperopia, longsightedness |
|---|
| hypermetropy | (noun) abnormal condition in which vision for distant objects is better than for near objects | Synonyms: farsightedness, hypermetropia, hyperopia, longsightedness |
|---|
| isometropia | (noun) equality of refractive power in the two eyes | - |
|---|
| ketotetrose | (noun) A monosaccharide that has both a ketone and four carbons. | - |
|---|
| magnetron | (noun) a diode vacuum tube in which the flow of electrons from a central cathode to a cylindrical anode is controlled by crossed magnetic and electric fields; used mainly in microwave oscillators | - |
|---|
| metro | (noun) an electric railway operating below the surface of the ground (usually in a city) | Synonyms: subway, subway system, tube, underground |
|---|
| metrology | (noun) the scientific study of measurement | - |
|---|
| metronidazole | (noun) antiprotozoal medication (trade name Flagyl) used to treat trichomoniasis and giardiasis | Synonyms: Flagyl |
|---|
| metronome | (noun) clicking pendulum indicates the exact tempo of a piece of music | - |
|---|
| metronymic | (noun) a name derived from the name of your mother or a maternal ancestor | Synonyms: matronymic |
|---|
| metropolis | (noun) people living in a large densely populated municipality | Synonyms: city |
|---|
| (noun) a large and densely populated urban area; may include several independent administrative districts | Synonyms: city, urban center |
| metropolitan | (noun) a person who lives in a metropolis | - |
|---|
| (noun) in the Eastern Orthodox Church this title is given to a position between bishop and patriarch; equivalent to archbishop in western Christianity | - |
| metroptosis | (noun) prolapse of the uterus | Synonyms: descensus uteri |
|---|
| metrorrhagia | (noun) bleeding from the uterus that is not due to menstruation; usually indicative of disease (as cervical cancer) | - |
|---|
| osteopetrosis | (noun) an inherited disorder characterized by an increase in bone density; in severe forms the bone marrow cavity may be obliterated | Synonyms: Albers-Schonberg disease, marble bones disease |
|---|
| petrochemical | (noun) any compound obtained from petroleum or natural gas | - |
|---|
| petroglyph | (noun) a carving or line drawing on rock (especially one made by prehistoric people) | - |
|---|
| petrol | (noun) a volatile flammable mixture of hydrocarbons (hexane and heptane and octane etc.) derived from petroleum; used mainly as a fuel in internal-combustion engines | Synonyms: gas, gasolene, gasoline |
|---|
| petrolatum | (noun) a semisolid mixture of hydrocarbons obtained from petroleum; used in medicinal ointments and for lubrication | Synonyms: mineral jelly, petroleum jelly |
|---|
| petroleum | (noun) a dark oil consisting mainly of hydrocarbons | Synonyms: crude, crude oil, fossil oil, oil, rock oil |
|---|
| petrology | (noun) the branch of geology that studies rocks: their origin and formation and mineral composition and classification | Synonyms: lithology |
|---|
| retro | (noun) a fashion reminiscent of the past | - |
|---|
| retrofit | (noun) the act of adding a component or accessory to something that did not have it when it was manufactured | - |
|---|
| (noun) a component or accessory added to something after it has been manufactured | - |
| retroflection | (noun) the act of bending backward | Synonyms: retroflexion |
|---|
| (noun) an articulatory gesture made by turning the tip of the tongue back against the roof of the mouth | Synonyms: retroflexion |
| (noun) a turning or tilting backward of an organ or body part | Synonyms: retroflexion, retroversion |
| retroflexion | (noun) the act of bending backward | Synonyms: retroflection |
|---|
| (noun) an articulatory gesture made by turning the tip of the tongue back against the roof of the mouth | Synonyms: retroflection |
| (noun) a turning or tilting backward of an organ or body part | Synonyms: retroflection, retroversion |
| retrogaming | (noun) The hobby of playing or collecting older video games and computer games. | - |
|---|
| retrogression | (noun) returning to a former state | Synonyms: regress, regression, retroversion, reversion |
|---|
| (noun) passing from a more complex to a simpler biological form | Synonyms: degeneration |
| retronym | (noun) a word introduced because an existing term has become inadequate | - |
|---|
| retrorocket | (noun) a small rocket engine on a larger rocket or spacecraft that is fired to slow or alter its course | - |
|---|
| retrospect | (noun) contemplation of things past | - |
|---|
| retrospection | (noun) memory for experiences that are past | - |
|---|
| (noun) reference to things past | - |
| retrospective | (noun) an exhibition of a representative selection of an artist's life work | - |
|---|
| retroversion | (noun) returning to a former state | Synonyms: regress, regression, retrogression, reversion |
|---|
| (noun) translation back into the original language | - |
| (noun) a turning or tilting backward of an organ or body part | Synonyms: retroflection, retroflexion |
| retrovirus | (noun) any of a group of viruses that contain two single-strand linear RNA molecules per virion and reverse transcriptase (RNA to DNA); the virus transcribes its RNA into a cDNA provirus that is then incorporated into the host cell | - |
|---|
| retrovision | (noun) a vision of events in the distant past | - |
|---|
| tetrode | (noun) a thermionic tube having four electrodes | - |
|---|
| tetrodotoxin | (noun) a powerful neurotoxin found in the ovaries of pufferfish | - |
|---|
| tetrose | (noun) any monosaccharide sugar containing four atoms of carbon per molecule | - |
|---|
| tetroxide | (noun) an oxide containing four atoms of oxygen in the molecule | - |
|---|
| thermometrograph | (noun) a thermometer that records temperature variations on a graph as a function of time | Synonyms: thermograph |
|---|