17-letter words containing a, e, r, o, s, i
- omphalomesenteric — (anatomy) Of or pertaining to the umbilicus and mesentery.
- on speaking terms — the act, utterance, or discourse of a person who speaks.
- on-street parking — parking (of a car, vehicle, etc) that is or is allowed to be done on a street
- one-time password — (security) (OTP) A security system that requires a new password every time a user authenticates themselves, thus protecting against an intruder replaying an intercepted password. OTP generates passwords using either the MD4 or MD5 hashing algorithms. The equivalent term "S/Key", developed by Bellcore, is a trademark of Telcordia Technologies, so the name OTP is used increasingly. See RFC 1760 - "The S/KEY One-Time Password System" and RFC 1938 - "A One-Time Password System".
- opening arguments — the statements or arguments provided by lawyers at the beginning of a trial
- operation sealion — the codename for Hitler's proposed invasion (1940) of Great Britain
- operations centre — a centre where activities of a business, organization, etc, are administrated and take place
- opisthobranchiate — (zoology) Of or pertaining to the Opisthobranchiata.
- optical isomerism — stereoisomerism in which the isomers are identical in molecular weight and most chemical and physical properties but differ in their effect on the rotation of polarized light.
- organ-pipe cactus — a treelike or columnar cactus, Lemaireocereus marginatus, of Mexico, having a central, erect spine surrounded by spreading spines in clusters of five to eight, and funnel-shaped, brownish-purple flowers.
- organic chemistry — the branch of chemistry, originally limited to substances found only in living organisms, dealing with the compounds of carbon.
- orifice discharge — Orifice discharge is a model for calculating how quickly a fluid will come out of a punctured vessel or pipe.
- osculating circle — circle of curvature.
- outside broadcast — An outside broadcast is a radio or television programme that is not recorded or filmed in a studio, but in another building or in the open air.
- over-compensation — a pronounced striving to neutralize and conceal a strong but unacceptable character trait by substituting for it an opposite trait.
- over-conservative — disposed to preserve existing conditions, institutions, etc., or to restore traditional ones, and to limit change.
- oversquare engine — An oversquare engine is an engine which has a cylinder bore that is larger than its stroke.
- pacific northwest — the region of North America lying north of the Columbia River and west of the Rockies
- pair of compasses — compass (def 7)
- paleobiochemistry — the study of biochemical processes that occurred in fossil life forms.
- paleoconservative — a person advocating an older, traditional type of conservatism, especially in politics.
- paradoxical sleep — REM sleep.
- parts per million — the number of units (of a substance) present in a million units of another substance
- passenger station — a station used by passengers
- pate de foie gras — See under foie gras.
- peloponnesian war — a war between Athens and Sparta, 431–404 b.c., that resulted in the transfer of hegemony in Greece from Athens to Sparta.
- peripheral vision — all that is visible to the eye outside the central area of focus; side vision.
- pernicious anemia — Pernicious anemia is a very severe blood disease.
- personal distance — personal space.
- personal equation — the tendency to personal bias that accounts for variation in interpretation or approach and for which allowance must be made.
- personality clash — friction between two people who have different personalities or points of view
- personnel carrier — a vehicle used for transporting troops
- perspicaciousness — having keen mental perception and understanding; discerning: to exhibit perspicacious judgment.
- perth and kinross — a council area of N central Scotland, corresponding mainly to the historical counties of Perthshire and Kinross-shire: part of Tayside Region from 1975 until 1996: chiefly mountainous, with agriculture, tourism, and forestry. Administrative centre: Perth. Pop: 135 990 (2003 est). Area: 5321 sq km (2019 sq miles)
- photo-respiration — the oxidation of carbohydrates in many higher plants in which they get oxygen from light and then release carbon dioxide, somewhat different from photosynthesis.
- phototherapeutics — the branch of therapeutics that deals with the curative use of light rays.
- pillion passenger — a person who travels in a seat or place behind the rider of a motorcycle, scooter, horse, etc
- point of purchase — designating or in use at a retail outlet where an item can be purchased; point-of-sale: point-of-purchase displays to entice the buyer.
- point reyes lilac — a prostrate shrub, Ceanothus gloriosus, of southern California, having leathery, roundish leaves and purplish or deep-blue flowers.
- point-of-purchase — designating or in use at a retail outlet where an item can be purchased; point-of-sale: point-of-purchase displays to entice the buyer.
- polar coordinates — Usually, polar coordinates. one of two coordinates used to locate a point in a plane by the length of its radius vector and the angle this vector makes with the polar axis (polar angle)
- portuguese guinea — former name of Guinea-Bissau.
- positive polarity — the grammatical characteristic of a word or phrase, such as delicious or rather, that may normally only be used in a semantically or syntactically positive or affirmative context
- post-and-rail tea — (in the 19th century) a coarse tea in which floating particles resembled a post-and-rail fence
- postal stationery — an envelope, postal card, wrapper, or aérogramme, with the stamp printed directly on the paper.
- postural drainage — a therapy for clearing congested lungs by placing the patient in a position for drainage by gravity, often accompanied by percussion with hollowed hands.
- potassium bromate — a white, crystalline, water-soluble powder, KBrO 3 , used chiefly as an oxidizing agent and as an analytical reagent.
- potassium bromide — a white, crystalline, water-soluble powder, KBr, having a bitter saline taste: used chiefly in the manufacture of photographic papers and plates, in engraving, and in medicine as a sedative.
- potassium nitrate — a crystalline compound, KNO 3 , produced by nitrification in soil, and used in gunpowders, fertilizers, and preservatives; saltpeter; niter.
- prairie provinces — the Canadian provinces of Manitoba, Saskatchewan, and Alberta, which lie in the N Great Plains region of North America: the chief wheat and petroleum producing area of Canada