18-letter words containing p, l, a, t, s
- optical microscope — traditional magnifying instrument
- optical soundtrack — the final soundtrack on a motion picture, which appears as a band of black and white serrations along a strip of film to the left of the composite print. Light is shined through the serrations and is converted to audible sound.
- oriental scops owl — any of a group of small owls having ear tufts and a whistling call, especially Otus scops (Old World scops owl) and O. sunia (Oriental scops owl)
- overspecialization — excessive specialization, as in a field of study.
- pair of spectacles — a score of 0 in each innings of a match
- paleoclimatologist — the branch of paleogeography dealing with the study of paleoclimates.
- parathyroid glands — any of several small oval glands usually lying near or embedded in the thyroid gland.
- parliamentarianism — advocacy of a parliamentary system of government.
- passing modulation — a modulation of a temporary nature.
- payload specialist — an astronaut trained to handle highly complex or classified equipment carried aboard a space shuttle and to conduct experiments in space.
- payment by results — a system of wage payment whereby all or part of the wage varies systematically according to the level of work performance of an employee
- 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.
- pedal steel guitar — an oblong, floor-mounted electrified guitar, usually having ten strings, fretted with a steel bar and producing a wailing sound that is modulated by use of a foot pedal.
- pellitory of spain — a small Mediterranean plant, Anacyclus pyrethrum, the root of which contains an oil formerly used to relieve toothache: family Asteraceae (composites)
- pennsylvania dutch — the descendants of 17th- and 18th-century settlers in Pennsylvania from southwest Germany and Switzerland.
- personal assistant — aide
- 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.
- 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.
- 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 chemistry — the branch of chemistry dealing with the relations between the physical properties of substances and their chemical composition and transformations.
- physical education — systematic instruction in sports, exercises, and hygiene given as part of a school or college program.
- physical inventory — To carry out a physical inventory is to count all the stock on hand.
- physical therapist — sb who performs physiotherapy
- pilotless aircraft — an aircraft equipped for operation by radio or by robot control, without a human pilot aboard; drone.
- 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.
- plumber's merchant — a shop or business that sells things needed for the job of installing and repairing pipes, fixtures, etc, for water, drainage, and gas
- 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.
- polynesian tattler — a sandpiper, H. incanus, native to the Pacific coastal regions
- population density — ratio: inhabitants to area
- population figures — population totals; statistics relating to the size of populations
- positively charged — having a positive charge
- post-revolutionary — of, pertaining to, characterized by, or of the nature of a revolution, or a sudden, complete, or marked change: a revolutionary junta.
- postal storage car — a railroad car for transporting unsorted mail.
- 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 sulphate — a soluble substance usually obtained as colourless crystals of the decahydrate: used in making glass and as a fertilizer. Formula: K2SO4
- predicate calculus — predicate logic
- preparatory school — a private or parochial secondary school, especially one boarding its students and providing a college-preparatory education.
- prepositional verb — a combination of verb and preposition, often with idiomatic meaning, differing from other phrasal verbs in that an object must always follow the preposition, as take after in The children take after their mother.
- presenile dementia — a form of dementia, of unknown cause, starting before a person is old