18-letter words containing o, p, e
- 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.
- photoelectric cell — photocell.
- photoisomerization — isomerization induced by light.
- photomorphogenesis — plant development that is controlled by light.
- photosensitization — to make (a material) photosensitive, as by the application of a photosensitive emulsion.
- physical education — systematic instruction in sports, exercises, and hygiene given as part of a school or college program.
- physical geography — the branch of geography concerned with natural features and phenomena of the earth's surface, as landforms, drainage features, climates, soils, and vegetation.
- physical inventory — To carry out a physical inventory is to count all the stock on hand.
- phytohemagglutinin — a lectin, obtained from the red kidney bean, that binds to the membranes of T cells and stimulates metabolic activity, cell division, etc.
- pick of the litter — objects strewn or scattered about; scattered rubbish.
- piecewise function — a function whose definition changes depending on the value of the independent variable
- pileolated warbler — either of two western subspecies of Wilson's warbler.
- pilgrim's progress — an allegory (1678) by John Bunyan.
- pilotless aircraft — an aircraft equipped for operation by radio or by robot control, without a human pilot aboard; drone.
- pilotless ignition — a system for igniting a gas burner, as in a gas range, furnace, or boiler, without the use of a pilot light.
- piperonyl butoxide — a light-brown liquid, C 1 9 H 3 0 O 5 , used chiefly as a synergist in certain insecticides.
- plains grasshopper — a large, destructive short-horned grasshopper, Brachystola magna, of the western U.S., marked by pinkish hind wings.
- plane of incidence — a plane determined by a given ray, incident on a surface, and the normal at the point where the incident ray strikes the surface.
- plane polarization — a type of polarization in which the electric vector of waves of light or other electromagnetic radiation is restricted to vibration in a single plane
- plane trigonometry — the branch of trigonometry dealing with plane triangles.
- planned parenthood — an organization that gives out information on the planning of the number and spacing of the births of one's children, as through the use of birth-control measures
- plate-glass window — a window that has glass which has been formed by rolling
- 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.
- play second fiddle — be considered less important
- play someone false — to deceive, cheat, hoodwink, or betray someone
- plenum ventilation — a system of mechanical ventilation in which fresh air is forced into the spaces to be ventilated from a chamber (plenum chamber) at a pressure slightly higher than atmospheric pressure, so as to expel foul air.
- plight one's troth — to make a promise of marriage
- pneumatic conveyor — a tube through which powdered or granular material, such as cement, grain, etc is transported by a flow of air
- point d'angleterre — a bobbin lace in which the design is worked out with either a needle or bobbin.
- point of departure — Nautical. the precise location of a vessel, established in order to set a course, especially in beginning a voyage in open water.
- point of no return — Aviation. the point in a flight at which an aircraft will lack sufficient fuel to return to its starting point.
- point of reference — A point of reference is something which you use to help you understand a situation or communicate with someone.
- point set topology — topology (def 2).
- point-bearing pile — a pile depending on the soil or rock beneath its foot for support.
- policeman's helmet — a Himalayan balsaminaceous plant, Impatiens glandulifera, with large purplish-pink flowers, introduced into Britain
- political prisoner — sb imprisoned for political dissidence
- political question — a question regarded by the courts as being a matter to be determined by another department of government rather than of law and therefore one with which they will not deal, as the recognition of a foreign state.
- politically-minded — (of a person or group of people) interested in the way power is achieved and used in a country or society (through government, policy-making, etc)
- pollen mother cell — one of the mother cells that produce four microspores by meiosis.
- polynesian tattler — a sandpiper, H. incanus, native to the Pacific coastal regions
- polystyrene cement — a purpose-made adhesive for fixing rigid polystyrene
- polyvinyl chloride — a white, water-insoluble, thermoplastic resin, derived by the polymerization of vinyl chloride: used chiefly for thin coatings, insulation, and pipings.
- pontifical college — the chief body of priests in ancient Rome.
- population balance — A population balance is a model showing particle sizes during a grinding process, which is used when designing a process.
- population density — ratio: inhabitants to area
- population figures — population totals; statistics relating to the size of populations
- porcupine anteater — an echidna or spiny anteater.
- portable equipment — Portable equipment is electrical equipment that can easily be moved from one place to another while in operation or while connected to the supply.
- portage la prairie — a city in S Manitoba, in S central Canada, W of Winnipeg.