18-letter words containing m, e, t, o, p, s
- optical microscope — traditional magnifying instrument
- outer automorphism — an automorphism that is not an inner automorphism.
- paleoclimatologist — the branch of paleogeography dealing with the study of paleoclimates.
- pathname separator — (file system) The character used to separate elements of a path or pathname. Under Unix and POSIX.1 compliant systems the pathname separator is the (forward) slash, in MS-DOS backslash serves the same purpose. For obvious reasons the no directory or file name can contain this character.
- performance artist — an artist that is involved in a theatrical presentation that incorporates various art forms, such as dance, sculpture, music, etc
- personal exemption — Your personal exemption is the amount of money that is deducted from your gross income before you have to start paying income tax.
- photochemical smog — air pollution containing ozone and other reactive chemical compounds formed by the action of sunlight on nitrogen oxides and hydrocarbons, especially those in automobile exhaust.
- photodecomposition — the breaking down of molecules by radiant energy.
- photoisomerization — isomerization induced by light.
- photomorphogenesis — plant development that is controlled by light.
- play cat and mouse — Also called cat and rat. a children's game in which players in a circle keep a player from moving into or out of the circle and permit a second player to move into or out of the circle to escape the pursuing first player.
- policeman's helmet — a Himalayan balsaminaceous plant, Impatiens glandulifera, with large purplish-pink flowers, introduced into Britain
- polystyrene cement — a purpose-made adhesive for fixing rigid polystyrene
- post-impressionism — a varied development of Impressionism by a group of painters chiefly between 1880 and 1900 stressing formal structure, as with Cézanne and Seurat, or the expressive possibilities of form and color, as with Van Gogh and Gauguin.
- postmaster general — the executive head of the postal system of a country.
- postmillenarianism — postmillennialism.
- postviral syndrome — debilitating condition occurring as a sequel to viral illness
- potassium chlorate — a white or colorless, crystalline, water-soluble, poisonous solid, KClO 3 , used chiefly as an oxidizing agent in the manufacture of explosives, fireworks, matches, bleaches, and disinfectants.
- potassium chloride — a white or colorless, crystalline, water-soluble solid, KCl, used chiefly in the manufacture of fertilizers and mineral water, and as a source of other potassium compounds.
- potassium fluoride — a white, crystalline, hygroscopic, toxic powder, KF, used chiefly as an insecticide, a disinfectant, and in etching glass.
- potassium myronate — sinigrin.
- potassium sulphate — a soluble substance usually obtained as colourless crystals of the decahydrate: used in making glass and as a fertilizer. Formula: K2SO4
- precious moonstone — moonstone (def 1).
- presumption of law — a presumption based upon a policy of law or a general rule and not upon the facts or evidence in an individual case.
- prism spectrometer — an optical device for measuring wavelengths, deviation of refracted rays, and angles between faces of a prism, especially an instrument (prism spectrometer) consisting of a slit through which light passes, a collimator, a prism that deviates the light, and a telescope through which the deviated light is viewed and examined.
- processionary moth — a moth of the family Thaumetopoeidae, esp the oak processionary moth (Thaumetopoea processionea), the larvae of which leave the communal shelter nightly for food in a V-shaped procession
- programme of study — the prescribed syllabus that pupils must be taught at each key stage in the National Curriculum
- prometheus unbound — a drama in verse (1820) by Shelley.
- provision merchant — a person or company in the business of retailing food and other provisions
- pseudo-competitive — of, pertaining to, involving, or decided by competition: competitive sports; a competitive examination.
- pseudo-symptomatic — pertaining to a symptom or symptoms.
- psychogalvanometer — a type of galvanometer for detecting and measuring psychogalvanic currents.
- ptomaine poisoning — (erroneously) food poisoning thought to be caused by ptomaine.
- pulmonic airstream — a current of lung air set in motion by the respiratory muscles in the production of speech.
- put the mockers on — stop, thwart
- raman spectroscopy — a form of spectroscopy which uses the Raman effect for studying molecules
- recess appointment — a person appointed to an office by the President of the United States without approval from the Senate because the Senate is in recess
- registered company — a company which has officially registered its business
- respiratory system — the system by which oxygen is taken into the body and an exchange of oxygen and carbon dioxide takes place; in mammals the system includes the nasal passages, pharynx, trachea, bronchi, and lungs.
- retirement pension — income: no longer at work
- seasonal promotion — Seasonal promotions are items marketed to customers at the appropriate time of year, such as coats in the winter and bathing suits in the summer.
- segmental phonemes — phonemes consisting of sound segments; hence, the vowel, consonant, and semivowel sounds of a language
- self-contemplation — the act or process of thinking about oneself or one's values, beliefs, behavior, etc.
- semiprecious stone — See at semiprecious.
- september holidays — a period of time in September when people do not have to go to school, college or work
- shipping documents — documents relating to the sending of a shipment of goods, for example containing details of contents, weight, value etc.
- shoot from the hip — the act of shooting with a bow, firearm, etc.
- shotgun microphone — a directional microphone with a narrow-angle range of sensitivity.
- simple enumeration — a procedure for arriving at empirical generalizations by haphazard accumulation of positive instances.
- sling psychrometer — a psychrometer so designed that the wet-bulb thermometer can be ventilated, to expedite evaporation, by whirling in the air.