18-letter words containing a, l, o, p
- passive vocabulary — all the words, collectively, that a person can understand
- pathologic anatomy — the branch of pathology dealing with the morphologic changes in tissues.
- payload specialist — an astronaut trained to handle highly complex or classified equipment carried aboard a space shuttle and to conduct experiments in space.
- peak-to-peak value — Peak-to-peak value is the maximum voltage change occurring during one cycle of alternating voltage or current.
- peano's postulates — a collection of axioms concerning the properties of the set of all positive integers, including the principle of mathematical induction.
- pectoral sandpiper — an American sandpiper, Calidris melanotos, the male of which, when courting, inflates its chest conspicuously.
- pellitory of spain — a small Mediterranean plant, Anacyclus pyrethrum, the root of which contains an oil formerly used to relieve toothache: family Asteraceae (composites)
- people trafficking — the practice of bringing immigrants into a country illegally
- people's democracy — (in Communist ideology) a country or form of government in transition from bourgeois democracy to socialism. In this stage there is more than one class, the largest being the proletariat, led by the Communist Party, which is therefore the dominant power
- percussion flaking — a method of forming a flint tool by striking flakes from a stone core with another stone or a piece of bone or wood.
- perlocutionary act — the action of affecting someone by uttering certain words
- personal allowance — the amount of money you are allowed to earn each year without paying tax
- personal assistant — aide
- personal bodyguard — a person employed to protect a particular person
- 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.
- personal insurance — insurance on personal risk, such as car insurance, health insurance or loss of earnings insurance
- personal organizer — a small notebook with sections for personal information, as dates and addresses.
- pescadores-islands — (used with a plural verb) Penghu.
- peter and the wolf — a composition by Sergei Prokofiev written in 1936. It is a children's story with both music and text, spoken by a narrator accompanied by the orchestra
- phanerocrystalline — (of a rock) having the principal constituents in the form of crystals visible to the naked eye.
- phantasmagorically — having a fantastic or deceptive appearance, as something in a dream or created by the imagination.
- phantom withdrawal — the unauthorized removal of funds from a bank account using an automated teller machine
- philharmonic pitch — a standard of pitch in which A above middle C is established at 440 vibrations per second.
- phosphatidylserine — any of a class of phospholipids occurring in biological membranes and fats
- 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.
- 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.
- pileolated warbler — either of two western subspecies of Wilson's warbler.
- pilotless aircraft — an aircraft equipped for operation by radio or by robot control, without a human pilot aboard; drone.
- 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
- platinocyanic acid — the hypothetical acid containing platinum and the cyano group, H 2 Pt(CN) 4 .
- 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.
- point d'angleterre — a bobbin lace in which the design is worked out with either a needle or bobbin.
- 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 football — a political issue that is continually debated but has not yet been resolved
- 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)
- 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.