18-letter words containing s, e, p, o
- payload specialist — an astronaut trained to handle highly complex or classified equipment carried aboard a space shuttle and to conduct experiments in space.
- peano's postulates — a collection of axioms concerning the properties of the set of all positive integers, including the principle of mathematical induction.
- peasant proprietor — a peasant who owns land, especially the land he or she tills.
- 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)
- pensioneer trustee — (in Britain) a person authorized by HMRC to oversee the management of a pension fund
- 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.
- percussion section — orchestra, group: drums, etc.
- percussion welding — a form of resistance welding in which the required pressure is provided by a hammerlike blow.
- perfect continuous — perfect progressive.
- performance artist — an artist that is involved in a theatrical presentation that incorporates various art forms, such as dance, sculpture, music, etc
- perish the thought — to die or be destroyed through violence, privation, etc.: to perish in an earthquake.
- pernicious anaemia — Pernicious anaemia is a very severe blood disease.
- 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 tschaikowsky — Peter Ilyich [il-yich] /ˈɪl yɪtʃ/ (Show IPA), Tchaikovsky, Peter Ilyich.
- peters' projection — a form of modified world map projection that attempts to reflect accurately the relative surface areas of landmasses, an approach which gives greater prominence (than do standard representations) to equatorial countries
- petite bourgeoisie — the portion of the bourgeoisie having the least wealth and lowest social status; the lower middle class.
- phanerocrystalline — (of a rock) having the principal constituents in the form of crystals visible to the naked eye.
- philosophy of life — any philosophical view or vision of the nature or purpose of life or of the way that life should be lived.
- phosphatidylserine — any of a class of phospholipids occurring in biological membranes and fats
- 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.
- 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.
- piecewise function — a function whose definition changes depending on the value of the independent variable
- 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.
- plains grasshopper — a large, destructive short-horned grasshopper, Brachystola magna, of the western U.S., marked by pinkish hind wings.
- 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
- plight one's troth — to make a promise of marriage
- point set topology — topology (def 2).
- 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.