18-letter words containing a, p, l, u, d
- population density — ratio: inhabitants to area
- population pyramid — a graph showing the distribution of a population by sex, age, etc.
- 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.
- pour cold water on — If someone pours cold water on a plan or idea, they criticize it so much that people lose their enthusiasm for it.
- predicate calculus — predicate logic
- presidential suite — a suite of rooms, as in a hotel, suitable for a president or other head of state.
- protocol data unit — (PDU) A packet of data passed across a network. The term implies a specific layer of the OSI seven layer model and a specific protocol.
- provably difficult — The set or property of problems for which it can be proven that no polynomial-time algorithm exists, only exponential-time algorithms.
- pseudo-socialistic — of or relating to socialists or socialism.
- pseudointellectual — a person exhibiting intellectual pretensions that have no basis in sound scholarship.
- pull one's head in — the upper part of the body in humans, joined to the trunk by the neck, containing the brain, eyes, ears, nose, and mouth.
- put a bold face on — to seem bold or confident about
- pyromucic aldehyde — furfural.
- pyrosulphuric acid — a fuming liquid acid made by adding sulphur trioxide to concentrated sulphuric acid. Formula: H2S2O7
- quartz-iodine lamp — a type of tungsten-halogen lamp containing small amounts of iodine and having a quartz envelope, operating at high temperature and producing an intense light for use in car headlamps, etc
- repayment schedule — a document detailing the specific terms of a borrower's loan, such as monthly payment, interest rate, due dates etc
- sodium-vapour lamp — a type of electric lamp consisting of a glass tube containing neon and sodium vapour at low pressure through which an electric current is passed to give an orange light. They are used in street lighting
- 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).
- spackling compound — spackle
- superciliary ridge — browridge.
- supraorbital ridge — browridge.
- thiosulphuric acid — an unstable acid known only in solutions and in the form of its salts. Formula: H2S2O3
- to hold your peace — If you hold or keep your peace, you do not speak, even though there is something you want or ought to say.
- unpledged delegate — (in the US) a delegate at a national party convention who is free to vote for any candidate
- upper middle class — wealthy, highly-educated people
- valle de la pascua — a city in N Venezuela.