20-letter words containing a, p, o, r
- sex change operation — a surgical operation designed to change a person's physical sexual characteristics to those of the opposite sex
- shakespearean sonnet — a sonnet form used by Shakespeare and having the rhyme scheme abab, cdcd, efef, gg.
- sharp-tailed sparrow — a sparrow, Ammospiza caudacuta, inhabiting salt marshes in North America, having narrow, sharply pointed tail feathers.
- south american plate — a major tectonic division of the earth's crust, comprising the continent of South America and several ocean basins and bounded on the north by the Caribbean Plate, on the east by the Mid-Atlantic Ridge, on the west by a submarine trench that borders the western coast of the continent, and on the south by the Antarctic Plate.
- south temperate zone — the part of the earth's surface between the tropic of Capricorn and the Antarctic Circle.
- span of apprehension — the maximum number of objects that can be correctly assessed after a brief presentation
- spanish oyster plant — a composite plant, Scolymus hispanicus, of southern Europe, having spiny, thistlelike leaf margins, small yellow flowers, and an edible root.
- special boat service — a unit of the Royal Marines specializing in reconnaissance and sabotage
- special patrol group — a former police unit tasked with counter terrorism in the Royal Ulster Constabulary
- special relationship — the exceptionally close political, diplomatic, cultural and historical relations between the United States and the United Kingdom
- specific performance — (especially in the sale of land) literal compliance with one's contractual promises pursuant to a judicial mandate.
- spectroscopic binary — a binary star having components that are not sufficiently separated to be resolved by a telescope, known to be a binary only bythe variations in wavelength of emitted light that are detected by a spectroscope.
- spherical aberration — variation in focal length of a lens or mirror from center to edge, due to its spherical shape.
- spherical coordinate — Usually, spherical coordinates. any of three coordinates used to locate a point in space by the length of its radius vector and the angles this vector makes with two perpendicular polar planes.
- spiral of archimedes — a curve that is the locus of a point that moves outward with uniform speed along a vector, beginning at the origin, while the vector rotates about the origin with uniform angular velocity. Equation (in polar coordinates): r = aθ.
- spirits of hartshorn — a colorless, pungent, suffocating, aqueous solution of about 28.5 percent ammonia gas: used chiefly as a detergent, for removing stains and extracting certain vegetable coloring agents, and in the manufacture of ammonium salts.
- spontaneous abortion — miscarriage (def 1).
- spontaneous recovery — the reappearance of a response after its extinction has been followed by a period of rest
- spontaneous-abortion — Also called voluntary abortion. the removal of an embryo or fetus from the uterus in order to end a pregnancy.
- spotted crane's-bill — the American wild geranium, Geranium maculatum.
- square of opposition — a diagrammatic representation of the opposition of categorical propositions.
- state highway patrol — a state's road traffic police
- step into the breach — If you step into the breach, you do a job or task which someone else was supposed to do or has done in the past, because they are suddenly unable to do it.
- subscription library — a commercial lending library
- supersonic transport — a commercial jet airplane that can fly faster than the speed of sound. Abbreviation: SST.
- switchboard operator — a person who operates an installation in a telephone exchange, office, hotel, etc, at which the interconnection of telephone lines is manually controlled
- teletype corporation — (company) The company which made Teletype teletypewriters. Address: Skokie, Illinois, USA.
- television programme — a programme broadcast on television
- the legal profession — the profession of law
- therapeutic abortion — abortion performed when a woman's pregnancy endangers her health.
- third-party software — software created by programmers or publishers independent of the manufacturer of the hardware for which it is intended.
- throw up one's hands — the terminal, prehensile part of the upper limb in humans and other primates, consisting of the wrist, metacarpal area, fingers, and thumb.
- to bring up the rear — If a person or vehicle is bringing up the rear, they are the last person or vehicle in a moving line of them.
- to clean up your act — If someone who has been behaving badly cleans up their act, they start to behave in a more acceptable or responsible way.
- to disturb the peace — If someone is accused of disturbing the peace, they are accused of behaving in a noisy and offensive way in public.
- to keep your balance — If you keep your balance, for example, when standing in a moving vehicle, you remain steady and do not fall over. If you lose your balance, you become unsteady and fall over.
- to keep your hand in — If you do something to keep your hand in, you practise a skill or hobby occasionally in order to remain fairly good at it.
- to make up your mind — If you make up your mind or make your mind up, you decide which of a number of possible things you will have or do.
- to overstep the mark — If someone oversteps the mark, they behave in a way that is considered unacceptable.
- to scrape the barrel — If you say that someone is scraping the barrel, or scraping the bottom of the barrel, you disapprove of the fact that they are using or doing something of extremely poor quality.
- to spread your wings — If you spread your wings, you do something new and rather difficult or move to a new place, because you feel more confident in your abilities than you used to and you want to gain wider experience.
- toxemia of pregnancy — an abnormal condition of pregnancy characterized by hypertension, fluid retention, edema, and the presence of protein in the urine.
- transformation point — a temperature at which the transformation of one microconstituent to another begins or ends during heating or cooling.
- transposed conjugate — adjoint (def 2).
- transposition cipher — a cipher that rearranges the letters of the plain text in a different sequence.
- tropical continental — a type of warm, dry air mass originating at low latitudes over land areas
- tropical disturbance — a very weak, or incipient, tropical cyclone.
- tropospheric scatter — transmission of radio frequency signals that have been scattered from irregularities in the troposphere to locations hundreds of kilometers distant.
- trumpet call for sth — a signal for something
- turn an honest penny — to earn money fairly and honestly