18-letter words containing h, o, m, p
- philharmonic pitch — a standard of pitch in which A above middle C is established at 440 vibrations per second.
- phosphonium iodide — a colorless to slightly yellowish, crystalline, water-soluble solid, PH 4 I, used in chemical synthesis.
- 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.
- phytohemagglutinin — a lectin, obtained from the red kidney bean, that binds to the membranes of T cells and stimulates metabolic activity, cell division, etc.
- pigmy hippopotamus — a related but smaller animal, Choeropsis liberiensis
- policeman's helmet — a Himalayan balsaminaceous plant, Impatiens glandulifera, with large purplish-pink flowers, introduced into Britain
- pollen mother cell — one of the mother cells that produce four microspores by meiosis.
- polychromatophilic — having an affinity for more than one kind of stain, especially for acid, neutral, and basic stains, as polychromatophilic erythroblasts characteristic of pernicious anemia.
- 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 sulphate — a soluble substance usually obtained as colourless crystals of the decahydrate: used in making glass and as a fertilizer. Formula: K2SO4
- pound the pavement — a paved road, highway, etc.
- 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
- programmer's cheer — (humour) "Shift to the left! Shift to the right! Pop up, push down! Byte! Byte! Byte!" [Origin?]
- projection machine — an apparatus that projects motion pictures; projector.
- prometheus unbound — a drama in verse (1820) by Shelley.
- propaganda machine — the group of people, publications, etc, such as of a government, country etc, responsible for the organized dissemination of information, allegations, etc, to assist or damage the cause of a government, movement, etc
- provision merchant — a person or company in the business of retailing food and other provisions
- psychogalvanometer — a type of galvanometer for detecting and measuring psychogalvanic currents.
- psychopharmacology — the branch of pharmacology dealing with the psychological effects of drugs.
- publishing company — a firm which publishes books
- put the mockers on — stop, thwart
- pygmy hippopotamus — a small hippopotamus, Choeropsis liberiensis, of forests and swamps in western Africa.
- pyromucic aldehyde — furfural.
- segmental phonemes — phonemes consisting of sound segments; hence, the vowel, consonant, and semivowel sounds of a language
- self-comprehending — to understand the nature or meaning of; grasp with the mind; perceive: He did not comprehend the significance of the ambassador's remark.
- 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.
- sling psychrometer — a psychrometer so designed that the wet-bulb thermometer can be ventilated, to expedite evaporation, by whirling in the air.
- sodium hyposulfite — sodium thiosulfate.
- something to spare — a surplus of something
- southampton island — an island in N Canada, in the Northwest Territories at the entrance to Hudson Bay. 19,100 sq. mi. (49,470 sq. km).
- spherical geometry — the branch of geometry that deals with figures on spherical surfaces.
- spur-of-the-moment — occurring or done without advance preparation or deliberation; extemporaneous; unplanned: a spur-of-the-moment decision.
- symphony orchestra — a large orchestra composed of wind, string, and percussion instruments and organized to perform symphonic compositions.
- systematic phoneme — a phonological unit in generative phonology representing an underlying form that takes into account the relationship between phonological patterns and morphological variation, as the unit underlying the second vowel in both derive and derivative.
- temporary hardness — hardness of water due to the presence of magnesium and calcium hydrogencarbonates, which can be precipitated as carbonates by boiling
- the bottomless pit — the underworld; hell
- the family compact — the ruling oligarchy in Upper Canada in the early 19th century
- the lords temporal — (in Britain) peers other than bishops in their capacity as members of the House of Lords
- the palmetto state — a nickname for South Carolina
- thought experiment — Physics. a demonstration or calculation that is based on the postulates of a theory, as relativity, and that demonstrates or clarifies the consequences of the postulates.
- three-body problem — the problem of calculating the motions of three bodies in space moving under the influence of only their mutual gravitational attraction.
- withdrawal symptom — effects of stopping a drug
- world championship — an international competition in a particular sport or activity for people all around the world