18-letter words containing a, p, l, i, e, d
- predicate calculus — predicate logic
- presenile dementia — a form of dementia, of unknown cause, starting before a person is old
- presidential suite — a suite of rooms, as in a hotel, suitable for a president or other head of state.
- primate of england — a title of the archbishop of Canterbury.
- principal meridian — a meridian line accurately laid out to serve as the reference meridian in land survey
- prisoner's dilemma — (in game theory) a scenario in which the outcome of one person's decision is determined by the simultaneous decisions of the other participants, resulting in a bad outcome for all of them if all act in their own self-interest.
- 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.
- pyromucic aldehyde — furfural.
- 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
- radical empiricism — (in the philosophy of William James) the doctrine that the only proper subject matter of philosophy is that which can be defined in terms of experience, and that relations are a part of experience.
- radical expression — an expression in which radical signs appear.
- reinforced plastic — plastic with fibrous matter, such as carbon fibre, embedded in it to confer additional strength
- resistance plasmid — any of a group of bacterial plasmids carrying genetic information that provide resistance to antibiotic drugs: some resistance plasmids are able to transfer themselves, and hence resistance, during conjugation
- retail price index — The retail price index is a list of the prices of typical goods which shows how much the cost of living changes from one month to the next.
- rhodes scholarship — one of a number of scholarships at Oxford University, established by the will of Cecil Rhodes, for selected students (Rhodes scholars) from the British Commonwealth and the United States.
- richard p. gabriel — Richard Gabriel
- scholarship holder — a person who, because of academic merit, receives financial aid for their studies
- seafloor spreading — a process in which new ocean floor is created as molten material from the earth's mantle rises in margins between plates or ridges and spreads out.
- secondary syphilis — the second stage of syphilis, characterized by eruptions of the skin and mucous membrane.
- self-deprecatingly — in a self-deprecating manner
- self-disparagement — the act of disparaging.
- september holidays — a period of time in September when people do not have to go to school, college or work
- shepherd satellite — a small moon orbiting near a planetary ring, whose gravitational pull helps confine the ring and the ring's extent.
- soda-lime feldspar — plagioclase.
- solitary sandpiper — a North American sandpiper, Tringa solitaria, of inland wetlands, having a brownish-gray, white-spotted back and whitish underparts.
- superciliary ridge — browridge.
- supraorbital ridge — browridge.
- the middle passage — the journey across the Atlantic Ocean from the W coast of Africa to the Caribbean: the longest part of the journey of the slave ships sailing to the Caribbean or the Americas
- traditional weapon — a weapon having ceremonial tribal significance, such as an assegai or knobkerrie
- upper middle class — wealthy, highly-educated people
- welland ship canal — a ship canal in S Canada, in Ontario, connecting Lakes Erie and Ontario: 8 locks. 25 miles (40 km) long.
- white-spotted hyla — a type of tree frog (H. leucophyllata) of tropical America
- wild passionflower — the maypop, Passiflora incarnata.
- wildlife programme — (esp on television) a documentary whose subject is wild animals in their natural habitat or undomesticated fauna and flora generally